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05-27-2020 Board Item 9_Seismic Evaluation - Volume 1
Prepared for: Orange County Sanitation District 10844 Ellis Avenue Fountain Valley, CA 92708-7018 (714) 593-7803 Project Report PS15-06 Seismic Evaluation of Structures at Plants 1 and 2 Prepared by: 2100 Main Street, Suite 150 Huntington Beach, CA 92648 Telephone: (714) 969-0800 Fax (714) 969-0820 www.geosyntec.com In Association with: Project Number: HL1635 July 19, 2019 7-19-19 7-19-19 7-19-197-19-19 7-19-19 HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx i 7/19/2019 TABLE OF CONTENTS Page LIST OF ACRONYMS AND ABBREVIATIONS ...................................................................... v EXECUTIVE SUMMARY ..................................................................................................... ES-1 1. INTRODUCTION ........................................................................................................... 1 2. SUMMARY OF EVALUATION APPROACH .............................................................. 3 2.1 Development of Project Approach ......................................................................... 3 2.2 Approach for Geotechnical Evaluations ................................................................. 3 2.2.1 Subsurface Site Model ............................................................................... 4 2.2.2 Seismic Setting and Response Spectra ...................................................... 4 2.2.3 Ground Deformations ................................................................................ 4 2.2.4 Geotechnical Input to Structural Analyses ................................................ 5 2.3 Approach for Structural Evaluations ...................................................................... 5 2.3.1 Seismic Evaluation Criteria ....................................................................... 5 2.3.2 Collect and Review As-built Information ................................................. 5 2.3.3 Conduct Site Visits .................................................................................... 6 2.3.4 Structural Analyses .................................................................................... 6 2.3.5 Identification of Potential Failure Modes .................................................. 9 2.4 Approach for Geotechnical and Structural Mitigations ........................................ 10 2.5 Basis for Risk Ranking of Seismic Projects ......................................................... 11 3. GEOTECHNICAL SUMMARY ................................................................................... 12 3.1 Seismic Setting and Design Earthquakes ............................................................. 12 3.2 Historic Document Review and Supplementary Field Investigation ................... 13 3.3 Idealized Soil Profiles .......................................................................................... 13 3.4 Liquefaction Analysis and Structural Inputs ........................................................ 13 3.5 Plant 1 Summary .................................................................................................. 14 3.5.1 Seismic Design Parameters ..................................................................... 14 3.5.2 Site Conditions ........................................................................................ 14 3.5.3 Geohazard Evaluation Results ................................................................. 15 3.6 Plant 2 Summary .................................................................................................. 15 3.6.1 Seismic Design Parameters ..................................................................... 15 3.6.2 Site Conditions ........................................................................................ 15 3.6.3 Geohazard Evaluation Results ................................................................. 16 4. RESULTS OF EVALUATIONS ................................................................................... 17 4.1 Introduction .......................................................................................................... 17 4.2 Seismic Mitigations Overview ............................................................................. 17 4.2.1 Structural Mitigations .............................................................................. 17 4.2.2 Geotechnical Mitigations ........................................................................ 18 4.3 Summary of Evaluation Results at Plant 1 ........................................................... 18 TABLE OF CONTENTS (Continued) Page HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx ii 7/19/2019 4.3.1 Potential Failure Modes ........................................................................... 18 4.3.2 Mitigation Alternatives ............................................................................ 19 4.4 Summary of Evaluation Results at Plant 2 ........................................................... 19 4.4.1 Potential Failure Modes ........................................................................... 19 4.4.2 Mitigation Alternatives ............................................................................ 20 4.5 Structure Summary Sheets ................................................................................... 20 5.MITIGATION COST ESTIMATING ........................................................................... 22 5.1 Structural Mitigations ........................................................................................... 22 5.1.1 Construction Difficulty ............................................................................ 23 5.1.2 Temporary Facilities ................................................................................ 23 5.2 Geotechnical Mitigations ..................................................................................... 23 5.2.1 Settlement and Lateral Earth Pressure Mitigation ................................... 23 5.2.2 Lateral Spread Mitigation ........................................................................ 23 5.3 Indirect Cost ......................................................................................................... 25 5.4 Facility Value ....................................................................................................... 25 6.LIKELIHOOD AND CONSEQUENCE RANKING .................................................... 26 6.1 Development of Likelihood of Seismic Failure Score ......................................... 26 6.2 Consequence Descriptions and Weights .............................................................. 26 6.2.1 Life Safety ............................................................................................... 26 6.2.2 Primary Treatment and Digestion ........................................................... 27 6.2.3 Regulatory ............................................................................................... 27 6.2.4 Stakeholder Commitments ...................................................................... 27 6.2.5 Financial Impacts .................................................................................... 27 6.2.6 Public Impacts ......................................................................................... 27 6.2.7 Summary of OCSD Input Regarding Consequences ............................... 28 6.3 Calculation of RoSF for each PFM ...................................................................... 28 6.3.1 BSE-1E vs BSE-2E ................................................................................. 28 6.4 Calculation of Structure RoSF ............................................................................. 29 6.4.1 Controlling Failure Type ......................................................................... 29 6.4.2 Controlling Consequence ........................................................................ 29 7.PROJECT RANKING ................................................................................................... 30 7.1 Risk Ranking Within Facility Master Plan Framework ....................................... 30 7.1.1 Based on Highest RoSF Score ................................................................. 30 7.1.2 Structures That Can Be Mitigated Using an Already Planned Project ...................................................................................................... 30 7.1.3 Structures Subject to Lateral Spread ....................................................... 30 7.2 Plant 1 Recommended Project Prioritization ....................................................... 31 7.2.1 1-8 Control Center ................................................................................... 31 7.2.2 1-9 12-kV Service Center ........................................................................ 31 TABLE OF CONTENTS (Continued) Page HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx iii 7/19/2019 7.2.3 1-31 Buildings 5 and 6 ............................................................................ 32 7.2.4 1-34 Laboratory Complex ....................................................................... 32 7.3 Plant 2 Recommended Project Prioritization ....................................................... 32 7.3.1 2-23 Surge Tower No. 1 .......................................................................... 32 7.3.2 2-27 Maintenance Building ..................................................................... 32 7.3.3 2-29 Ocean Outfall Booster Pump Station .............................................. 33 7.4 Integration with the Facility Master Plan (FMP) ................................................. 33 7.4.1 Overview of FMP Prioritization .............................................................. 33 7.4.2 Approach to Integration with the FMP .................................................... 34 7.4.3 Proposed Initiative for CoSE ................................................................... 34 7.4.4 Remaining Integration Steps ................................................................... 35 8. SUMMARY ................................................................................................................... 36 9. REFERENCES ............................................................................................................... 37 HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx iv 7/19/2019 LIST OF TABLES Table 4.1: Standard Structural Mitigations Table 4.2: Standard Geotechnical Mitigations Table 5.1: Facility Values, Plant 1 Table 5.2: Facility Values, Plant 2 Table 6.1: Structure Occupancy, Plant 1 Table 6.2: Structure Occupancy, Plant 2 Table 6.3: Controlling Failure and Controlling Consequence, Plant 1 Table 6.4: Controlling Failure and Controlling Consequence, Plant 2 Table 7.1: Prioritized List of Recommended Mitigations with Costs, Plant 1 Table 7.2: Prioritized List of Recommended Mitigations with Costs, Plant 2 LIST OF FIGURES Figure 1.1: Project Approach Flowchart Figure 4.1: Results of Structural Evaluations at Plant 1 Figure 4.2: Results of Structural Evaluations at Plant 2 Figure 7.1: Project Prioritization Approach LIST OF APPENDICES Appendix A: Technical Memorandum 2 Appendix B: Technical Memorandum 3 Appendix C: Meeting Minutes Appendix D: Seismic Evaluation Criteria Appendix E: Structure Summary Sheets Appendix F: Mitigation Cost Tables Appendix F1: Structural Mitigation Cost Tables Appendix F2: Geotechnical Mitigation Cost Tables Appendix G: Lateral Spread Wall Concept Memorandum Appendix H: Likelihood and Consequence of Each PFM, by Structure HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx v 7/19/2019 LIST OF ACRONYMS AND ABBREVIATIONS AACEI American Association of Cost Engineers International ACI America Concrete Institute ANSYS ANSYS Finite Element Software API American Petroleum Institute ASCE American Society of Civil Engineers ASTM American Society of Testing and Materials AWL analysis water level bgs below ground surface BH borehole BRBF buckling restrained braced frame BSE Basic Safety Earthquake CBC California Building Code CBSC California Building Standards Commission CCI Construction Cost Index CDMG California Department of Conservation, Division of Mines and Geology CH fat clay CIP Capital Improvement Program CL lean clay CMU concrete masonry unit CoSF Consequence of Seismic Failure CPT cone penetration tests DAFT Dissolved Air Flotation Thickener DCR demand-to-capacity ratio DS differential settlement EPRI Electric Power Research Institute FC fines content FE finite element FHWA Federal Highway Administration ft feet, foot FMP Facility Master Plan GDR Geotechnical Data Report GS ground shaking GWRS Groundwater Remediation System HHWL historic high-water level IF importance factors in. inches IO immediate occupancy LDI lateral displacement index LIST OF ACRONYMS AND ABBREVATIONS (cont’d) HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx vi 7/19/2019 LLRS lateral load resisting system LOS levels of service LoF Likelihood of Failure LoSF Likelihood of Seismic Failure Score LPILE Computer program LS lateral spread MAC Mechanical and Compressor ML inorganic silt NHI National Highway Institute MSL mean sea level O&M Operation and Maintenance OCHCA Orange County Health Care Agency OCSD Orange County Sanitation District OOBS Ocean Outfall Booster Station OOP out-of-plane PEPS Primary Effluent Pump Station PFM potential failure mode PGA peak ground acceleration PGD Permanent Ground Displacements PT peat PS Planning Study RAS Return Activated Sludge RC reinforced concrete RoF Risk of Failure RS Response Spectrum RUL Remaining Useful Life SCAL Secondary Clarifiers A-L SEI Structural Engineering Institute SM silty sand SP poorly graded sand SPT Standard Penetration Testing TM Technical Memorandum USCS Unified Soil Classification System USGS United States Geological Survey WSSPS Waste Sidestream Pump Station HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx ES-1 7/19/2019 EXECUTIVE SUMMARY This final project report is the fourth and final technical memorandum developed by the Geosyntec team for the “PS15-06 Seismic Evaluation of Structures at Plants 1 and 2” project. The overall focus of this study was to evaluate the seismic vulnerability of select structures at the two plants and develop recommendations for the mitigation of the identified vulnerabilities. Each of the three technical memoranda developed prior to this final report provides interim work products related to the three main tasks in the scope of work. Technical Memorandum 1 (TM1), developed at the conclusion of Task 1, provides a preliminary characterization of the seismic vulnerabilities at each plant based on a review of background documents and sets forth an initial framework for the project approach. As the study progressed, the approach was adjusted and refined to efficiently meet the goals of the project. The updated approach is described in Section 2 of this report and supersedes the information provided in TM1. Technical Memorandum 2 (TM2), included as Appendix A, summarizes the geotechnical field investigations performed as part of this study and includes laboratory test data obtained from the soil samples collected during the investigations. Technical Memorandum 3 (TM3), included as Appendix B, provides a description of the geotechnical and structural evaluations performed in Task 2 and Task 3, respectively. Identified vulnerabilities and mitigation recommendations to address the identified vulnerabilities are presented in Potential Failure Mode (PFM) and Mitigation Tables, both of which are provided in appendices to TM3. The final project task, Task 4, includes an estimation of planning-level budgetary construction costs to implement the recommended mitigations to address the seismic vulnerabilities identified in Task 3. This task also includes prioritization of the relative importance of implementing the various recommended mitigation measures, given the likelihood and consequence associated with each PFM. Mitigation costs, prioritization, and recommendations for Plants 1 and 2 are summarized in Tables 7.1 and 7.2. In addition to describing the final project approach, this Project Report presents the evaluation of the cost and effectiveness of proposed mitigations and provides a list of recommended mitigation measures given the prioritization of vulnerabilities. Considerations for incorporating seismic projects into Orange County Sanitation District’s (OCSD’s) Facility Master Plan (FMP) are also provided. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 1 7/19/2019 1. INTRODUCTION Orange County Sanitation District (OCSD) initiated this PS15-06 study due to concerns about the resiliency of Plants 1 and 2 in a significant seismic event. Many of the structures at each plant were designed and built prior to the adoption of modern building codes and, as such, there was the need to conduct an evaluation of potential seismic hazards and associated retrofits to mitigate the risk of earthquake damage. This study focuses on critical structures that were designed and built using codes prior to the 2001 California Building Code (CBC). The scope of work of this project includes an assessment of the seismic vulnerability of these facilities using the general approach described in American Society of Civil Engineers (ASCE) 41-13 for existing structures. Based on the identified seismic vulnerabilities, recommendations for seismic improvements and planning level cost estimates have been developed to enhance the performance and operational reliability of these facilities to meet target seismic performance levels. Working with OCSD, a process was developed to prioritize and provide relative rankings for implementation of the recommended improvements. The primary elements of the overall study were as follows. 1. Review existing structural and geotechnical data to understand existing conditions and identify data gaps in existing information. 2. Conduct limited geotechnical investigations at the two plants (detailed in TM2; Appendix A) to evaluate geologic site hazards, including estimates of ground motion, liquefaction potential, and liquefaction-induced differential settlement and lateral spreading (detailed in TM3; Appendix B). 3. Conduct performance-based seismic evaluations of the selected structures at the two plants using ASCE 41-13 and America Concrete Institute (ACI) 350-06 guidelines and other applicable standards (detailed in TM3; Appendix B). 4. Identify geotechnical and structural mitigation measures to achieve target performance levels for the selected structures at the two plants. These performance levels were initially identified by OCSD and include immediate occupancy, life safety, or collapse prevention. depending on the risk category assigned to the structure (detailed in TM3; Appendix B). 5. Develop an American Association of Cost Engineers International (AACEI) Concept Screening phase (Class 5) cost estimate for the recommended improvements and retrofits. 6. Prepare this final report (also referred to as Technical Memorandum 4; TM4) that presents the results of this study, identifies the potential seismic risk to the selected structures, and provides a prioritized list of mitigation measures to meet the selected performance levels. This document was prepared by a consultant team consisting of Geosyntec Consultants, Carollo Engineers, and InfraTerra (the Geosyntec team). During the course of the project, the Geosyntec team solicited input from OCSD stakeholders regarding the preparation of this document, the selected approaches, and the results of these HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 2 7/19/2019 evaluations during a series of workshops and meetings. Minutes of these meetings are included in Appendix C. Work performed for this project was reviewed by OCSD’s Independent Technical Reviewer, Jacobs Engineering. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 3 7/19/2019 2. SUMMARY OF EVALUATION APPROACH 2.1 Development of Project Approach A preliminary project approach was presented in Technical Memorandum (TM1), which was used by the team as guidance for the study. During the course of the project, elements of the approach evolved based on additional data, discussions with OCSD and OCSD’s third-party reviewer, Jacobs Engineering. The sections below describe the final project approach that supersedes TM1. The final project approach generally followed the framework and evaluation procedures set forth in ASCE 41-13. Where necessary, adjustments were made to the ASCE 41-13 approach to more efficiently achieve the project goals, accommodate non-building structures such as process tanks to maintain uniformity in the overall approach, and efficiently achieve project goals for both building and non-building structures. These adjustments were also necessary because of the liquefaction hazard at the sites. Specific adjustments made to the ASCE 41-13 framework are outlined in the discussion of the geotechnical and structural evaluation approaches that follow. 2.2 Approach for Geotechnical Evaluations At each plant, the geotechnical evaluation approach generally consisted of the following steps: • Develop a subsurface site model; • Evaluate the seismic setting and associated ASCE 41-13 response spectra for target seismic hazard levels; • Evaluate ground deformations from associated geohazards1, including: o Liquefaction-induced settlement; and o Liquefaction-induced lateral spreading; • Support structural analyses with geotechnical input, as appropriate, including: o Axial and lateral foundation capacities; o Anchor capacities (Plant 2); o Soil resistance for foundation springs; and o Lateral earth pressures for buried structural elements; • Develop geotechnical mitigation measures; and • Develop cost estimates for geotechnical mitigation. 1 Fault rupture was originally considered as an additional source of ground deformation for Plant 2. However, as described in TM3, given the low probabilities of fault rupture and the comparatively large liquefaction-induced deformations being considered at the plant site, the Geosyntec team did not incorporate fault rupture deformations within the evaluations considered for these existing structures. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 4 7/19/2019 2.2.1 Subsurface Site Model A subsurface site model for each plant was developed using existing data supplemented with data collected from targeted geotechnical investigations performed as part of this study. The site model included development of subsurface stratigraphy at each structure included in the study, as well as generally for the two plants, including assigning groundwater levels to be used for analyses. Geotechnical parameters were assigned to each soil stratum using both the existing data and data collected from geotechnical investigations. Details of the targeted geotechnical investigation at both plants are included in TM2. Interpreted subsurface conditions at each plant and for each structure are presented in TM3. 2.2.2 Seismic Setting and Response Spectra Plants 1 and 2 are located in Southern California, an area of relatively high seismic hazard. Development of the seismic setting included a review of historical seismicity and known seismic sources within the vicinity of the plants. The review considered both local (such as the Newport- Inglewood and San Joaquin Hills Faults) and regional (such as the San Andreas fault) seismic sources. ASCE 41-13 [2014] defines two earthquake levels referred to as Basic Safety Earthquake (BSE) 1 and 2. For existing structures, the two earthquake levels (BSE-1E and BSE-2E) are defined as ground motions with a 20% and 5% probability of exceedance in 50 years (equivalent return periods of 225 years and 975 years), respectively. Seismic response spectra were developed for each plant for the BSE-1E and BSE-2E ground motion levels. Further details of the seismic setting and the ASCE 41-13 response spectra developed for the plants are included in TM3. 2.2.3 Ground Deformations Using the subsurface site model and the estimated ground shaking, liquefaction analysis was performed for each structure. The analysis included an assessment of liquefaction triggering and the associated vertical settlements and lateral spread deformations. Analyses were performed for up to five cone penetration tests (CPTs). “Best estimate”2 idealized settlement and lateral spread profiles were developed for each structure. Results of liquefaction analysis, including the estimated amplitude and deformation profiles for liquefaction-induced settlement and lateral spread, were used as input to the structural analyses. Additional details of the ground deformation analysis methodology and the results for each structure are included in TM3. 2 Settlement and lateral spread values were also developed representing an “upper” estimate interpretation of the results from the CPTs; however, for the purposes of a planning study, it was deemed more appropriate to focus on best estimate behavior, and so structural analyses were not widely performed at these upper estimates, and they were instead considered only qualitatively. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 5 7/19/2019 2.2.4 Geotechnical Input to Structural Analyses Foundation-specific geotechnical parameters, such as pile and anchor capacities, lateral earth pressures, soil springs, and bearing capacities were developed for use in structural analysis. Details of these geotechnical inputs to structural analysis are included in TM3. 2.3 Approach for Structural Evaluations The approach for seismic evaluation of structures can be summarizes as follows: • Establish the seismic evaluation criteria: o Selection of a performance objective; o Define the building performance levels; o Define the seismic hazard levels; and o Define geotechnical and geo-seismic loads and soil deformation; • Collect and review as-built information; • Conduct site visits to confirm as-built conditions and identify deficiencies in conformance with a Tier 1 evaluation; • Perform structural analyses: o Tier 1 (where applicable); o Tier 2 or equivalent (as required); and o Tier 3 or equivalent (as required); • Identify potential failure modes (PFMs); • Develop mitigation strategies; and • Develop cost estimates for structural mitigation. 2.3.1 Seismic Evaluation Criteria Seismic evaluation criteria for the structures were originally developed as part of TM1 and are included herein as Appendix D. Through the course of the study, the structure criticality and associated performance levels were revised for multiple structures and new structures were added and some structures omitted from the original scope of work. The final list of structures included within Appendix D contains a summary of OCSD’s assigned Structure Class and Risk Category. 2.3.2 Collect and Review As-built Information Before beginning the seismic evaluations of the structures, it was necessary to collect information about the structures to establish sufficient knowledge of their framing systems and overall configuration to guide the evaluation. Drawings for projects were made available by OCSD, including general, civil, structural, mechanical, and standard/typical detail sheets. In many cases, these drawings were labeled as “record” or “as-built” drawings. The drawings served as the initial HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 6 7/19/2019 basis for understanding of structural systems. For further discussion of the collection and review of as-built information, refer to Section 3.1 of TM3. 2.3.3 Conduct Site Visits Prior to structural analyses, site visits were conducted for each structure to allow for collection of visual information. The site visits were conducted at both Plants 1 and 2 between January 10, 2018 and February 11, 2018. Observations made during the site visits were collected using digital cameras, iPads, hand-written notes, and other media capturing devices. Information was collected, compiled, and organized by structure for use by the evaluation team using standard data forms. For a discussion of the site visits, refer to Section 3.2 of TM3. 2.3.4 Structural Analyses The structural seismic evaluation of each structure included both an analytical and visual assessment. The analytical review was a quantitative estimate of the potential material stresses and deformation of the structural members when subjected to estimated loads due to the loading from the considered seismic hazard. The visual assessment was a qualitative evaluation of the structural condition, which can have a bearing on the available structural capacity. The goal of this evaluation was to identify those structural vulnerabilities and conditions, whether by analytical or visual assessment methods, that have a potential to significantly impact the ability of the facility to meet the stated performance goals and, as required, recommend mitigation measures that will improve the performance of the structure. The structural seismic evaluation work was limited to actions and conditions that are brought about by seismic activity, such as inertial and convective response to ground shaking, inertial soil pressures, liquefaction conditions, lateral spreading, and dynamic settlement. The structural seismic evaluations did not include analyses to assess the structural response to the following independent load cases and/or conditions that occur apart from the seismic load case or apart from conditions brought about by site seismic activity: • Service loads; • Wind loads; • Construction loads; • Static uniform and differential settlement effects; • Thermal expansion and/or contraction; • Flood loads; or • Tsunami loads. While fault traces have been identified at Plant 2, fault rupture hazard at Plant 2 has been shown to have a relatively low risk of occurrence compared to structural shaking and liquefaction hazards. As described in further detail in TM3, a study by Kleinfelder [2017] indicates that the median horizontal fault rupture displacement associated with the BSE-1E and BSE-2E seismic hazard levels are both zero. Consequently, the structural response to fault rupture for structures at both Plants 1 and 2 were not evaluated. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 7 7/19/2019 The seismic evaluation of the structures at Plant 1 and Plant 2 generally followed the guidelines and recommendations set forth in ASCE 41-13 with some adjustments made to the typical evaluation process depicted in Figure C1-1 of ASCE 41-13 [2014]. One of the goals of the study was to identify PFMs for the subject structures, which does not necessarily require extensive structural analysis or multi-tiered evaluations to achieve. Additionally, the study includes non-building structures and a large quantity of structures that required adjustments to the ASCE 41-13 evaluation framework in order to efficiently manage and execute the structural assessment. The primary adjustments made to the traditional application of the ASCE 41-13 evaluation framework are as follows: • For evaluating the structure response to ground deformation, ASCE 41-13 requires that the structure be evaluated using the Tier 3 procedures. Through the course of the geotechnical work, it became evident that many structures would be potentially subjected to high ground deformations due to liquefaction. Since it was not practical to analyze each affected structure to the Tier 3 level, 11 structures were identified as “exemplar” structures according to their general building type and configuration. Ground deformation analyses were then prepared for the exemplar structures and then those findings were applied to each structure considered to be similar to a given exemplar structure. These similar structures are referred to within this study as “subsidiary” structures. Variations in the subsidiary structures compared to their exemplar were taken into consideration when applying the exemplar findings. This evaluation process for the subsidiary structures was referred to as a “Tier 1/Tier 2” evaluation. The exemplar structures and their corresponding subsidiaries are identified in TM3. • Several of the structures are concrete water-bearing structures. Typically, such structures are designed and evaluated using the provisions established in ACI 350. However, because one of the major goals of the study is to prioritize mitigation of the structures for planning purposes, it became important to maintain a uniform approach to the seismic evaluation. ACI 350, unlike ASCE 41-13, is intended for the design of new concrete water-bearing structures and includes design parameters, such as importance factors, load factors, capacity-reduction factors, R-factors, and numerous other parameters that have no direct correlation with ASCE 41-13. Therefore, the seismic hazards and structural performance of the water-bearing structures were evaluated following ASCE 41-13 with revisions to ACI 350 parameters (identified subsequent to this list). For the seismic hazard definition, this process was essentially equivalent to that for buildings, but for estimation of the available capacity, it was necessary to classify investigated structural performance as being force controlled or displacement controlled. The classification of these structural actions is documented in the PFM tables prepared for each structure and provided as Appendix E to TM3. Where the structural action being evaluated did not have a similar action defined in the corresponding material chapter of ASCE 41-13, the action was conservatively assumed to be force controlled. • Water-bearing structures were not subjected to a Tier 1 evaluation, as set forth in ASCE 41-13, except where the water-bearing structure is comprised of a lateral load-resisting system that is included in one of the building types identified in Table 3-1 of ASCE HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 8 7/19/2019 41-13 [2014]. For example, the Plant 1 Aeration Basins were classified as a Type C2 structure and were evaluated at the Tier 1 level. Other water-bearing structures that did not have a Tier 1 analysis were comprehensively evaluated to a level that is similar to a Tier 2 evaluation and have been noted as such throughout the documents prepared for this study. • For all structures, the evaluation was limited to the lowest Tier per ASCE 41-13, unless a higher tier evaluation was planned or considered to improve accuracy in the findings. Higher Tier evaluations were planned for exemplar structures and used elsewhere when the Tier 1 findings were considered to be too conservative in nature. The following conditions generally warranted stopping the evaluation at the Tier 1 level: o Tier 1 deficiencies significantly exceed the stress/deformation levels considered to be acceptable for the evaluated performance level. In such cases, by experience, further evaluation using the Tier 2 or Tier 3 procedures is considered to have a very low likelihood of having a compliant outcome. In general, demand-to-capacity ratios (DCRs) that exceed 2.0 have a low likelihood of overturning a finding from non-compliant to compliant. o The Tier 1 deficiency is non-quantitative in nature and the deficiency cannot reasonably be modeled or evaluated. For example, the absence of structural foundation ties is a deficiency that cannot reasonably be evaluated because those elements do not exist. Without an alternative load path or redundant system, the response of the structure is pre-judged to have a performance that cannot meet the evaluated performance level. Many of the non-building environmental concrete structures, such as the digesters and aeration basins, have structural systems, loads, and load paths that are not similar to buildings. Therefore, the non-building concrete structures were evaluated using additional considerations provided in ACI 350.3-06, "Seismic Design of Liquid-Containing Concrete Structures and Commentary," recognizing that no other relevant comprehensive seismic evaluation guides or standards are available for concrete tanks. For example, the development of hydrodynamic loads is well established in ACI 350.3-06. Similarly, steel gas holders and steel domes, where they occur, were evaluated with additional input from American Petroleum Institute (API) 650, “Welded Tanks for Oil Storage.” Since these standards are primarily written for new design, modifications for their adaptation to seismic evaluation were necessarily addressed as follows: • Importance factors were assumed to be equal to 1.0; • Capacity-reduction factors were assumed to be equal to 1.0. This practice is repeatedly recommended throughout the material chapters of ASCE 41-13 [2014]; and • Load factors and load combinations per ASCE 41-13 were used. Analyses were performed at both the BSE-1E and BSE-2E seismic hazard levels for each structure. Discussions about the analysis for each structure or group of structures are provided in TM3. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 9 7/19/2019 2.3.5 Identification of Potential Failure Modes Each structure was evaluated for potential failure modes according to the type of structure and its exposure to geo-seismic hazards. For each structure, PFMs were defined and tracked through the evaluation. The PFMs were identified both before the start of the evaluation and during the evaluation, as the process of evaluating the structures inherently allows for the identification of PFMs. Evaluated PFMs were generally of three types, namely: those due to structural shaking; those due to differential settlement due to liquefaction; and those due to lateral spread. An example of a structural PFM for a building is the failure of a wall anchorage connection between a concrete wall and a steel deck diaphragm. This type of PFM is common to building types with heavy walls and light-weight roof framing systems and is applicable to many of the structures evaluated. The seismic analysis involves the estimation of seismic load and deformation demands placed upon structural members. These demands are compared against their estimated capacity, which is a function of the member proportions, material properties, and desired performance level. The metric primarily used in this evaluation to quantify the degree of distress of an existing member or connection is referred to as the “demand-to-capacity ratio” or DCR. DCR =Load Demand Available Capacity DCR values that exceed 1.0 have been considered as exceeding their capacity for the evaluated performance level, and the investigated PFM is considered a deficiency. PFMs were tracked for each structure, and the results of whether the PFM was a deficiency or not is identified in the PFM tables for each structure. However, not all deficiencies will limit the performance of a building. Engineering judgment was used to determine how the deficiency impacts the operation of the facility. Those deficiencies that have little to no consequence, such as a high localized shear stress in a concrete wall, were excluded from the list of PFMs being considered. Some PFMs were found to meet the performance objectives and are noted as such in the PFM table for each structure. The estimated capacity is a function of the material properties. For this evaluation, the material properties have been obtained from the record construction documents. For Tier 2 investigations and beyond, ASCE 41-13 [2014] requires that a knowledge factor be applied to the material property depending on what type of construction documents the material information was obtained from. For any Tier 2 evaluations, a knowledge factor of 0.75 was applied where the material properties were not specified on the construction documents. A knowledge factor of 0.90 was applied where the material properties were obtained from the construction drawings, specifications, mill certificates, or material test results. Information regarding the material properties was available for nearly all structures. The condition of the structure was also considered in the evaluation. Where concrete or reinforcing steel was found to be deteriorated and/or corroded, an estimate of the reduced material HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 10 7/19/2019 properties was estimated based on the information in the corrosion assessment report for that particular structure or structures of a similar age and type. 2.4 Approach for Geotechnical and Structural Mitigations PFMs identified for the structures were categorized as being caused by either ground shaking or ground deformation. Where PFMs due to ground shaking were identified for a structure, structural mitigation to improve the structure performance to the levels established in the criteria for each PFM were developed. Several common structural deficiencies were identified, and standard structural mitigation techniques were developed to address them. Structural deficiencies that are unique to a particular structure were also identified in the study. Structural mitigation for these deficiencies were developed on a case-by-case basis. In each case, an attempt was made to define the scope of the mitigation for both standard and custom mitigation approaches. In many cases, a single mitigation approach was determined to address multiple deficiencies. For example, numerous deformation and connection detail deficiencies at the Plant 1 Control Center can be mitigated by adding steel- braced frames to both stories of the building. Development of structural mitigation measures was limited to structure modifications that may involve removal of structural elements, replacement of structural elements/members, strengthening of existing elements, revision to framing systems, and provision of additional seismic load resisting elements. Complete structure replacement and operational strategies were not considered in the development of the structural mitigation measures. Where the structure could not meet demands imposed by ground deformations, geotechnical ground improvement measures were developed to reduce the magnitude of seismically induced settlement, lateral spread deformation, or lateral earth pressure. Development of the geotechnical mitigations was assessed to meet structural criteria for deformation or earth pressure reduction needed to meet performance criteria. These mitigation measures are described in further detail in TM3. Development of the mitigations did not involve the preparation of design calculations or documentation to prove compliance with any building code or seismic retrofit standard. Rather, the degree of deficiency, known from the analysis, was considered, and the amount of mitigation generally required to improve the performance to the levels required was estimated. For example, to address excessive roof diaphragm shear, the area of the roof that was estimated to exceed the acceptable limit of shear stress was included in the quantity take-off for the recommended mitigation. The evaluations conducted in this report are for planning purposes. Detailed design would ultimately be needed to be completed for each structure to be retrofitted. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 11 7/19/2019 2.5 Basis for Risk Ranking of Seismic Projects To prioritize each seismic project compared to the other seismic projects, a risk score was developed, similar to the way it was developed for the Facility Master Plan (FMP), i.e., Risk of Seismic Failure (RoSF) = Likelihood of Seismic Failure (LoSF) x Consequence of Seismic Failure (CoSF). When this was completed, the seismic projects were sorted from highest risk to lowest risk to establish the priority rankings/groupings. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 12 7/19/2019 3. GEOTECHNICAL SUMMARY A geotechnical evaluation was performed for each subject structure utilizing a sequenced approach. As part of this study, the Geosyntec team assessed the seismic setting and developed seismic design parameters, reviewed existing historic geotechnical data and field investigation information, performed supplementary field investigations, and for each subject structure, established idealized subsurface soil profiles, performed liquefaction triggering analyses, estimated liquefaction-induced ground deformation profiles, and developed geotechnical parameters as input to the structural analyses. A brief synopsis of each phase in the geotechnical evaluation is provided below along with a summary of plant-specific geotechnical site conditions, seismic design parameters, and results from the geohazard evaluation. Note that all phases of the geotechnical assessment outlined herein were performed as previous tasks to this report, and detailed descriptions and methodologies are provided in TM2 (Appendix A) and TM3 (Appendix B). 3.1 Seismic Setting and Design Earthquakes OCSD Plants 1 and 2 are located in Southern California, an area of relatively high seismicity, and significant seismic sources in the vicinity of the site include active faults with movement or evidence of activity in the last 11,000 years (Holocene age). Major seismic sources near the two plants include the Newport-Inglewood Fault Zone, the San Joaquin Hills fault, and the Palos Verdes fault. The San Andreas Fault, at a distance of greater than 70 kilometers, is considered a far-field, yet more probable (i.e., more frequent), seismic source for both Plants in the next 30 years. ASCE 41-13 [2014] defines two earthquake levels referred to as BSE 1 and 2 (BSE-1 and BSE-2). Two earthquake levels are provided such that a structure experiences little damage from relatively frequent, moderate earthquakes, but significantly more damage and potential economic loss from the most severe and infrequent earthquakes. For this study, the 225-year return period BSE-1E and the 975-year return period BSE-2E ground motion levels were selected for seismic assessment of Plant 1 and Plant 2 structures. Response spectra were developed at the BSE-1E and BSE-2E levels, assuming stiff soil (Site Class D) conditions using the USGS seismic design maps per ASCE 41-13 [2014] and ASCE 7-10 [2010]. Note that per ASCE 7-10, the presence of liquefiable soils indicates that the appropriate classification is Site Class F. However, as liquefaction typically results in changes to response spectra at longer periods and the target Plant 1 and 2 structures generally have short fundamental periods, it was considered appropriate to perform strong shaking analyses using the unliquefied Site Class D response spectra. More detail on the regional seismic setting and ground motion parameter selection process is provided in Section 4.1.1 of TM3. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 13 7/19/2019 3.2 Historic Document Review and Supplementary Field Investigation Due to their seismic setting and dense infrastructure footprint, Plants 1 and 2 have both been the subject of numerous past geotechnical studies. As part of the Task 1 document review and data gap identification process, a review of available historical geological and geotechnical data was performed. Following the review of historical information, geotechnical investigations were performed at both plants between January 29th and February 28th, 2018 as part of Task 2. The investigation included 28 CPTs advanced to depths between 65 feet (ft) and 100 ft below ground surface (bgs) at Plant 1 and between 80 ft and 100 ft at Plant 2, six mud rotary borings advanced to depths of between 91 ft and 101 ft bgs at Plant 1 and between 80 ft and 100 ft at Plant 2, and a laboratory testing program on collected soil samples. The purpose of the investigation was to provide supplementary geotechnical information in support of the seismic structural analyses, with added emphasis along the Santa Ana River and Talbert Marsh frontages, near critical structures (e.g., Class I structures) and in regions with limited historical investigation information available. The complete details of the field investigation are provided in TM2. 3.3 Idealized Soil Profiles Following the site investigation and historic geotechnical data review, site-specific geotechnical parameters were developed at each plant as part of Task 3, and unique structure-specific subsurface idealized soil profiles and material properties were developed for each subject structure based on historic and recent geotechnical investigations. These idealized profiles were used in the ground deformation and seismic structural analyses. The methodologies and approaches for developing the soil profiles and material properties are discussed in Sections 4.1.2 and 4.1.3 of TM3 and include evaluation of subsurface conditions and assessment of groundwater levels, respectively. 3.4 Liquefaction Analysis and Structural Inputs Experiences from previous earthquakes have demonstrated that loose granular soils located near the ground surface and saturated by a high-water table are the most susceptible to liquefaction. The loss of strength associated with liquefaction can cause settlement, flotation of buried structures, increase in lateral soil pressures, and bearing capacity reduction below shallow foundations or around deep foundation elements. A related phenomenon is lateral spreading, where liquefied soil located near a vertical face or sloping ground, such as near the Santa Ana River and Talbert Marsh, moves as a mass towards the face and can apply lateral forces to structures and their foundations. The idealized structure-specific soil conditions and seismic design parameters were used to perform liquefaction triggering analyses in Task 3 for each subject structure. Liquefaction-induced ground settlement and lateral spread deformation profiles were estimated at each subject structure and provided as input to the structural analyses. In addition to the liquefaction ground deformation information provided in the seismic analyses, foundation-specific geotechnical parameters were developed in Task 3 in support of the structural assessments, including differential settlement across the foundation, pile and anchor capacities, lateral earth pressures, soil springs, and bearing capacities for both liquefied and unliquefied HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 14 7/19/2019 scenarios. The settlement and lateral spread deformation profiles and foundation-specific geotechnical parameters developed for use in the structural analyses are discussed in greater detail in Sections 4.1.4 and 4.1.5 of TM3, respectively. 3.5 Plant 1 Summary 3.5.1 Seismic Design Parameters In both the 20% (BSE-1E) and 5% (BSE-2E) in 50-year hazard scenarios, the demand was sufficiently high to trigger liquefaction in the underlying potentially liquefiable soils at Plant 1. Once liquefaction has triggered and the soil loses its capacity to resist shear stresses, calculated permanent vertical reconsolidation strains (i.e., settlement) and shear strains (i.e., lateral displacement) develop at depth with little sensitivity to the demand level; therefore, only the 5% in 50-year (BSE-2E) hazard level was used to assess liquefaction-induced permanent ground deformations at Plant 1. The liquefaction triggering and deformation results and the ground deformation inputs to the structural analysis presented in TM3 were based on the probabilistic BSE-2E (5% in 50 years) hazard level magnitude of M7.71 and PGA of 0.46g. 3.5.2 Site Conditions Plant 1 is situated along the Santa Ana River within the Santa Ana Gap, which is bounded by the Huntington Beach Mesa to the northwest and Newport Mesa to the southeast. The Santa Ana Gap began to fill with sediment towards the end of the Pleistocene Era as the sea level began to rise and deposits from the river merged with marine deposits. In its present state, the site is mostly flat with a levee along the Santa Ana River and a concrete retaining wall at the river’s edge. Boring logs from past geotechnical investigations indicate that the majority of the site is overlain by approximately 2 to 8 ft of fill and suggest that the material below this depth is comprised of alluvial and estuarian deposits. Ongoing facility improvements at Plant 1 appear to have had little additional impact on the overall site grade. Information from geotechnical reports dating back to the early 1960’s suggests that the ground surface at that time was within approximately 2 to 3 ft of its current elevation. In general, a silty sand (Unified Soil Classification System [USCS]: SM) layer extends from the ground surface to approximately 15 to 25 ft bgs. This includes the shallow fills present at existing grade. This layer is underlain by a 15- to 25-ft thick inorganic clay (USCS: CL or CH) with intermittent inorganic silt (USCS: ML) layers. Potential peat or other organic soil (USCS: PT) seams were encountered within this layer. Below approximately 40 ft bgs, lies a continuous SM layer. At some locations within this layer, an intervening 5- to 10-ft thick CL or CH layer was found. This clay material appears to be more intermittent with increasing distance from the Santa Ana River. A higher degree of continuity in material type and layer thickness was observed closer to the river channel. Additional information on subsurface conditions is provided in Section 4 of TM3. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 15 7/19/2019 3.5.3 Geohazard Evaluation Results The liquefaction-induced deformation profiles developed at each subject structure were used to estimate settlement and lateral spread at the ground surface at Plant 1 as part of Task 3. The resulting best estimate of liquefaction-induced settlement and lateral spread expressed at the ground surface at Plant 1 is shown adjacent to each subject structure in Figure 4.17 of TM3 (Appendix B). A map of the liquefaction-induced surface settlement was generated as shown in Figure 4.18 of TM3 to highlight those structures in the most susceptible areas of liquefaction. Settlement at the ground surface was found to vary between 3 and 9 inches (in.) across the Plant 1 site. Differential settlement due to liquefaction was estimated to be on average 40% in 60 ft of the total settlement. Additionally, contours of the liquefaction-induced lateral spread at the ground surface at Plant 1 are shown in Figure 4.19 of TM3 and are based on the ground surface lateral spread predicted at each structure. The best estimate lateral spread was estimated to be on the order of 3 ft for the study structures nearest the Santa Ana River frontage and reducing to zero at the approximate limit of lateral spread. Additional information on the geohazard quantification and evaluation results are provided in Section 4 of TM3. 3.6 Plant 2 Summary 3.6.1 Seismic Design Parameters In both the 20% (BSE-1E) and 5% (BSE-2E) in 50-year hazard scenarios, the demand was sufficiently high to trigger liquefaction in the underlying potentially liquefiable soils at Plant 2. Once liquefaction has triggered and the soil loses its capacity to resist shear stresses, calculated permanent vertical reconsolidation strains (i.e., settlement) and shear strains (i.e., lateral displacement) develop at depth with little sensitivity to the demand level; therefore, only the 5% in 50-year (BSE-2E) hazard level was used to assess liquefaction-induced permanent ground deformations at Plant 2. The liquefaction triggering and deformation results and the ground deformation inputs to the structural analysis presented in TM3 were based on the probabilistic BSE-2E (5% in 50 years) hazard level magnitude of M7.71 and PGA of 0.48g. 3.6.2 Site Conditions Plant 2 is also located within the Santa Ana Gap, downstream of Plant 1 and near the mouth of the Santa Ana River. The generally level site is bounded by the Santa Ana River to the east and southeast and Talbert Marsh to the south and southwest. Boring data from geotechnical investigations indicate that the site is underlain by approximately 3 to 6 ft of fill. The data show that ground surface elevations at developed portions of the site generally increased by 0 to 3 ft during the time period spanned by the past geotechnical reports. Based on review of the data, the site appears to be characterized by relatively consistent subsurface stratigraphy. Below the ground surface, a CL to CH and ML interval are present that extends to a depth of approximately 8 to 10 ft bgs. This includes the shallow fills present at the site. This layer is underlain by a 50- to 60-ft thick SM and poorly graded sand (SP) layer. An ML and silty slay (CL-ML) layer with some intermittent SM seams is present at 60 to 85 ft bgs. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 16 7/19/2019 The soils below 85 ft bgs appear to consist of SP. Additional information on subsurface conditions is provided in Section 4 of TM3. 3.6.3 Geohazard Evaluation Results The liquefaction-induced deformation profiles developed at each subject structure were used to estimate settlement and lateral spread at the ground surface at Plant 1 as part of Task 3. The resulting best estimate of liquefaction-induced settlement and lateral spread expressed at the ground surface at Plant 2 is shown adjacent to each subject structure in Figure 4.22 of TM3 (Appendix B). A map of the liquefaction-induced surface settlement was generated, as shown in Figure 4.23 of TM3, to highlight those structures in the most susceptible areas of liquefaction. Settlement was found to vary between 3 and 13 in. across the Plant 2 site. Differential settlement due to liquefaction was estimated to be on average 40% in 60 ft of the total settlement. Additionally, contours of the liquefaction-induced lateral spread at the ground surface at Plant 2 are shown in Figure 4.24 of TM3 and are based on the ground surface lateral spread predicted at each structure. The best estimate lateral spread was estimated to be on the order of 4 to 6 ft for structures near the Santa Ana River frontage and 5 ft for structures near the Talbert Marsh frontage, eventually reducing to zero at the approximate limit of lateral spread. Additional information on the geohazard quantification and evaluation results are provided in Section 4 of TM3. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 17 7/19/2019 4. RESULTS OF EVALUATIONS 4.1 Introduction The structural evaluation of the structures at Plant 1 and Plant 2 involved multi-tiered structural analyses using procedures and methods set forth in ASCE 41-13, ACI 350, and API 650, with adjustments as required to suit the goals of the study previously described. The seismic shaking and ground deformation demands were applied to the structures, and the resulting structure member stresses and deformations were estimated and compared to the acceptance criteria for the defined performance level for each structure. PFMs were identified, tracked, and evaluated for each structure. PFMs were generally either related to the structural response to ground shaking, differential settlement due to liquefaction, or lateral spread. Structures that exhibit vulnerability related to at least one PFM were identified as failing to meet the seismic performance criteria. Where PFMs were found to be deficiencies (i.e., in cases in which DCRs exceed 1.0 for their evaluated performance levels, mitigation strategies were developed). Where mitigation is required to address structural deficiencies due to ground shaking, a structural mitigation strategy was developed. Likewise, where mitigation is required to address structural deficiencies due to response to differential settlement or lateral spread, a geotechnical mitigation strategy was developed. 4.2 Seismic Mitigations Overview 4.2.1 Structural Mitigations Structural mitigation measures were developed to address structural deficiencies caused by ground shaking. Structural mitigation was not developed to address structural deficiencies caused by differential settlement or lateral spread. Because numerous structural deficiencies were identical or similar for many of the buildings being evaluated, a set of standard structural mitigation approaches was identified and developed. The standard structural mitigation approaches are described in Table 4.1. Many of the structures were found to have unique structural deficiencies that required development of a customized structural mitigation approach. Also, for some structures, it was advantageous to address multiple structural deficiencies through a single structural mitigation approach or technique. The structural mitigations are summarized for each structure and presented in the Mitigation Tables located in Appendix F of TM3. The summary tables describe the deficiency requiring mitigation, the recommended mitigation, and notes regarding the application of the mitigation. The Mitigation Tables also include standard geotechnical mitigation approaches, which are described in the following section. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 18 7/19/2019 4.2.2 Geotechnical Mitigations A set of standard geotechnical mitigations was developed to address structural vulnerabilities related to ground deformations (liquefaction-induced differential settlement and lateral spread) and increased lateral earth pressure against submerged walls. These vulnerabilities cannot be efficiently mitigated by structural modifications. Standard geotechnical mitigations to address lateral spread include a high-shear resistance soil- mixed gravity wall (Mitigation A1) that can be constructed where sufficient space for installation between buried utilities exists, and a more rigid pipe pile cantilever wall (Mitigation A2) that can be constructed within narrow (<10 ft) corridors between existing utilities. Where lateral spread mitigations are implemented, it is likely that a combination of these two mitigation approaches, or other related approaches developed during the detailed evaluation and design process, will be used. Details of evaluations conducted for the cantilever pipe pile wall concept which illustrate that potential approach are included in Appendix G. Differential settlements exceeding structure tolerances can be addressed by Mitigation B1 (ground improvement below the entire structure footprint) or Mitigation B2 (ground improvement below perimeter footings), depending on the structure foundation footprint. Mitigation C (ground improvement adjacent to submerged portions of structures) was developed to mitigate increased lateral earth pressure due to liquefaction. Each standard geotechnical mitigation is described in additional detail in Table 4.2. 4.3 Summary of Evaluation Results at Plant 1 4.3.1 Potential Failure Modes Potential failure modes for the structures at Plant 1 are summarized for each structure in Appendix E of TM3. After evaluation, not all of the PFMs were found to be deficiencies with respect to the required performance level. However, numerous PFMs were found to be deficiencies. For buildings, some of the common and significant deficiencies identified include the following: • Insufficient capacity of the connection of the concrete or masonry walls to the roof and/or floor levels; • Insufficient shear strength in steel roof deck welds and/or steel ledger anchorage to concrete and masonry walls; • General building instability due to a lack of connections between the building walls and the footings or between the building walls and the floor slab; • Discontinuous shear walls and incomplete load paths (identified at four structures); • Insufficient strength for moment frames (at the Control Center); • Under-sized beams at chevron-braced frames (at Buildings 5 and 6 and the Central Laboratory); HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 19 7/19/2019 • Excessive overturning forces at braced-frame columns (at the Central Laboratory); • Insufficient separation between adjacent structures occurring between the digester pump room buildings and the digesters; and • Wall and foundation damage due to differential settlement caused by liquefaction. Structures with this deficiency are generally limited to those structures located within a few hundred feet of the Santa Ana River. For water-bearing and non-building structures, some of the common deficiencies include the following: • Excessive bending and/or shear failure of driven piles due to horizontal lateral spread displacements. Structures with this deficiency are generally limited to those structures located with a few hundred feet of the Santa Ana River. • Separation across expansion joints due to lateral spread at the Secondary Clarifiers. This deficiency is also estimated to destabilize the conveyor support framing that traverses over the expansion joints. 4.3.2 Mitigation Alternatives Recommended mitigations to address structure deficiencies are summarized for each structure in Appendix F of TM3. 4.4 Summary of Evaluation Results at Plant 2 4.4.1 Potential Failure Modes Potential failure modes for the structures at Plant 2 are summarized for each structure in Appendix E of TM3. After evaluation, not all of the PFMs were found to be deficiencies with respect to the required performance level. However, numerous PFMs were found to be deficiencies. For buildings, some of the common and significant deficiencies identified include the following: • Insufficient capacity of the connection of the concrete or masonry walls to the roof and/or floor levels; • Insufficient shear strength in steel roof deck welds and/or steel ledger anchorage to concrete and masonry walls; • Discontinuous shear walls and incomplete load paths (identified at six structures); • Insufficient flexural and axial strength for moment frame beams and columns (at the Maintenance Building); and • Wall and foundation damage due to differential settlement caused by liquefaction. Structures with this deficiency are generally limited to those structures located near the Santa Ana River and/or the Talbert Marsh. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 20 7/19/2019 For water-bearing and non-building structures, some of the common deficiencies include the following: • Walls, slabs, and foundation damage due to differential settlement due to liquefaction. Structures most impacted by this deficiency are located relatively close to the Santa Ana River and/or Talbert Marsh; • Separation across expansion joints due to differential settlement at the Secondary Clarifiers; and • Excessive bending and/or shear failure of piles due to horizontal lateral spread displacements at Surge Tower No. 1. 4.4.2 Mitigation Alternatives Recommended mitigation to address structure deficiencies are summarized for each structure in Appendix F of TM3. 4.5 Structure Summary Sheets To synthesize the information developed as part of this study, key information for each subject structure was condensed to a two-page structure summary sheet. In addition to providing basic information about the subject structure, such as building number associated with this study, plant number, structure class and risk category, and structure type, the following sections are provided: • schematic cross section and plan view – an oblique aerial image of the subject structure is shown along with a plan map showing the location of the subject structure (outlined in red) relative to other structures in this study (outlined in black) and non-PS15-06 structures (outlined in grey). The locations of CPTs (solid-blue triangles) and borings (blue-circled pluses) identified in this study are also shown on the map. The schematic cross section shows the structure-specific idealized soil profile (see Section 3.3) along with the general foundation type and configuration. The historic high-water level (HHWL) and analysis water level (AWL) are shown in the cross section and also tabulated as both depth bgs and mean sea level (MSL) elevation. Further discussion on ground water levels is provided in TM3. • class-based performance objectives – a brief description of the structure class performance objective as it pertains to wastewater flow and treatment and life loss. • structural components – identifies the key structural components, including foundation and structure type/dimensions, number of stories, date of original construction, previous retrofits and projects, and available documentation. This information was gathered in Task 1 and 3 from as-built structural drawings and information provided by OCSD. • geohazards and seismicity – a tabulation of the design earthquake parameters and resulting deformation at the ground surface from the structure-specific liquefaction assessment. The deterministic and probabilistic seismic hazards were developed HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 21 7/19/2019 (see Section 3.1 above) and the liquefaction-induced surface settlement and lateral spread were estimated from deformation profiles (see Section 3.4 above) in Task 3. • structural assessment and failure modes – PFMs were developed as part of Task 3 for each structure, and the resulting PFM number and description, tier level used to identify the PFM, and the results from the evaluation are tabulated. Note that PFMs that meet both the BSE-1E and BSE-2E performance objectives are omitted from the list, and additional PFMs considered are discussed in Sections 4.3.1 and 4.4.1 for Plant 1 and 2, respectively. If applicable, the associated exemplar structure is also provided for reference. • mitigation measures and costs – PFMs that did not meet both the BSE-1E and BSE-2E performance objectives were assigned a recommended mitigation measure, and the geotechnical and structural mitigation, cost, and comments on the mitigation are tabulated in this section. Descriptions of Standard Structural and Geotechnical Mitigations are discussed in Sections 4.2.1 and 4.2.2, respectively. The cost estimates are AACEI Class 5 “Order-of-Magnitude” estimates, are intended for planning purposes only, and were developed in Task 4, as described further in Section 5. • risk ranking – each structure was given a risk ranking evaluation in Task 4, as described further in Section 6. The results of this analysis are shown in the plot of likelihood of seismic failure versus consequences of seismic failure. The subject structure is shown as a red star, and all other structures at the plant are shown as grey circles. In addition, the controlling failure type, controlling consequences, and risk ranking values are also summarized. For structures where future projects are already planned, the next planned project and date are provided at the bottom of the second page. The structure summary sheets for each subject structure in this study are provided in Appendix E. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 22 7/19/2019 5. MITIGATION COST ESTIMATING This section provides a summary of mitigation construction costs for each structure at Plant 1 and Plant 2 where mitigations were identified. It is understood that these estimates will be used as a basis for planning future related retrofit projects. Appendix F provides details of the costs for structural and geotechnical mitigations proposed. The project team evaluated the seismic vulnerability of structures at Plant 1 and Plant 2 and recommended appropriate mitigation methods. Construction cost estimates for both mitigation and facility value were prepared in accordance with AACEI guidelines for projects in the Concept Screening phase (Class 5). Estimates prepared at this class are generally prepared at a very early stage of project definition and are therefore expected to have a wide uncertainty range (-50% to +50%). Mitigation costs are construction costs only, and do not include “soft” project costs. OCSD’s project controls group should add project costs when seismic projects are budgeted. This will provide accuracy and consistency with the other projects in the overall capital improvement program. 5.1 Structural Mitigations Mitigation costs related to structural items are presented for each structure in Appendix F1. The project team used the following procedures to produce uniformity and consistency while preparing cost estimates. Direct costs were identified to address each PFM having a seismic vulnerability. Mitigation costs for each structure are a summation of costs of all PFMs for the structure. • Cost estimates were prepared using OCSD’s standard cost estimating templates for planning projects. • Cost estimates were prepared as fully burdened construction costs (i.e., representative of a contractor's bid number). • All construction costs were prepared in terms of November 2018 dollars using a Los Angeles Engineering News-Record (ENR) Construction Cost Index (CCI) of 12,006. • The following procedures were followed when prior projects were used as a reference for a cost estimate: o Mid-point of construction for the referenced project was identified; and o Construction costs were escalated from the referenced project’s mid-point of construction using the applicable ENR CCI for mid-point of construction to November 2018 using the Los Angeles ENR CCI for November 2018 of 12,006. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 23 7/19/2019 5.1.1 Construction Difficulty For each PFM mitigation method, a value for construction difficulty and work restrictions was added. This cost item included the following: • Cost to comply with operations and sequencing restrictions; and • Cost and efforts for minimizing construction impacts on existing equipment and systems. 5.1.2 Temporary Facilities A temporary facilities cost was added to each structure based on the amount of time required to implement the desired mitigation method. This time allowance was estimated based on typical construction times and recognition that some structures would require working off hours and, therefore, require more time. The cost for this item included the following: • Contractors trailers; • Utilities; and • Support facilities. 5.2 Geotechnical Mitigations A fully burdened construction cost estimate was developed for each structure requiring settlement and/or lateral earth pressure mitigation. Additionally, cost estimates were developed for three circumstances related to providing lateral spread mitigation, one at Plant 1 and two at Plant 2. Geotechnical mitigation cost estimates are presented in Appendix F2. 5.2.1 Settlement and Lateral Earth Pressure Mitigation For differential settlement mitigation, estimates for permeation grouting to improve liquefiable soils beneath each affected structure were prepared, taking into account access restrictions and the depth of required treatment. Estimates were also prepared for permeation grouting around the perimeter of submerged walls where mitigation against increased lateral earth pressure is necessary. Ground improvement estimates were prepared assuming the most practical means of construction for each structure, with consideration given to structure configuration and recognizable logistical constraints. Assumed unit rates for drilling and grout pipe installation, along with unit rates for grout injection were used as the basis of the cost estimates. The costs associated with the potential temporary relocation of fixed equipment or appurtenant features, or unavoidable structure downtime that may be required during ground improvement operations, were not considered. 5.2.2 Lateral Spread Mitigation As described in Section 4.2.2, standard geotechnical mitigations identified to address lateral spread include a high-shear resistance soil-mixed gravity wall (Mitigation A1) and a pipe pile HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 24 7/19/2019 cantilever wall (Mitigation A2). Cost estimates were prepared for the following three lateral spread mitigation circumstances for use by OCSD in planning of potential related mitigations: • Along the length of Plant 1 Santa Ana River frontage; • Along only the portions of the Plant 2 Santa Ana River frontage and Talbert Marsh frontage where lateral spread mitigations would be indicated for structures that are the subject of this study; and • Along the length of both the Santa Ana River frontage and Talbert Marsh frontage at Plant 2. Where lateral spread mitigations are implemented, it is likely that a combination of the two mitigation approaches (A1 and A2) and other approaches developed during the detailed design of these mitigations will be used. Geosyntec’s approach to preparation of the cost estimate for lateral spread mitigation was developed in recognition of this uncertainty in the ultimate project definition and the expected level of accuracy of the AACEI Class 5 estimate at the project concept phase. As a basis for the estimate, preliminary evaluations were performed to assess the structural requirements and associated costs for a pipe pile wall (Approach A2) capable of resisting the load imposed by laterally spreading liquefied soils near the Plant 1 digesters. These evaluations and cost basis are described in Appendix G. The large-diameter drilled pipe piles were selected as an initial basis for the cost estimating exercise because they represent a space-efficient solution to reduction of lateral spreading. However, there are several mitigating circumstances around this cost basis: • More detailed analyses (i.e., 2D or 3D seismic numerical modeling) may identify more cost-efficient solutions to the reduced-footprint pipe pile cantilever wall concept; • Where a larger footprint is available, more cost-effective solutions (such as Approach A1) may be used and should be reflected in the mitigation cost estimate; and • Some portions of the frontage which were assumed to require lateral spread mitigation may not require it once consideration is given, during analysis and/or design, to effects of other existing or planned improvements associated with foundations of other structures (i.e., planning level analyses did not consider the presence of existing ground improvement or the effects of existing deep foundations in reducing the magnitude of lateral spreading). On this basis, the pipe pile conceptual approach used on a large scale is believed to represent something near the high end of the AACEI Class 5 estimate range for the lateral spread mitigation at the Plant 1 site. While a specific evaluation was not conducted at the Plant 2 site, it is assumed similarly that the evaluation conducted at Plant 1 can be considered a reasonable basis for a higher end estimate. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 25 7/19/2019 Considering the factors outlined above, Geosyntec judged that the estimated cost associated with the Approach A2 type wall should be reduced to represent a “best estimate” cost for large-scale lateral spread mitigation. Applying a reduction to discount this high-end (+50%) estimate to the “best estimate” results in a total estimated cost range to protect only the subject structures at Plant 1 from approximately $50M to $150M, with a best estimate of $100M. Total estimated cost to protect only the subject structures at Plant 2 ranges from approximately $25M to $75M, with a best estimate of approximately $50M. Alternatively, the cost to provide lateral spread mitigation along the full river and marsh frontage at Plant 2 was estimated to be approximately $125M to $350M, with a best estimate of $225M. Refer to the Lateral Spread Mitigation Cost Estimate table in Appendix F2 for additional detail. 5.3 Indirect Cost The following percentages for the cost estimating template were used for indirect costs: • Sales Tax (applied to half of direct costs): 8 percent; • Project Level Allowance: 30 percent; • General Conditions: 15 percent; • Contractor’s Profit: 10 percent; • Bid Bond: 2 percent; and • Insurance: 2 percent. 5.4 Facility Value Facility values were taken from the 2017 Facility Master Plan Valuation Report or generated in a similar manner. Each value represents the cost to construct the existing structure in 2017 dollars. Facility values were used as an indication of the potential financial consequences of seismic failure. They may also be used to compare the cost of seismic mitigation to the facility value; however, it should be noted that replacement cost may differ significantly from the facility value because replacement may require additional costs for demolition of the existing facility, geotechnical improvements to address seismic hazards, and upgrades for the new facility. Tables 5.1 and 5.2 identify the facility values that were used in this study. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 26 7/19/2019 6. LIKELIHOOD AND CONSEQUENCE RANKING 6.1 Development of Likelihood of Seismic Failure Score As this project consisted of an evaluation of seismic projects only, LoSF was evaluated based on the likelihood that a structure would sustain damage for the evaluated seismic hazard level that renders it unable to meet its performance requirements. LoSF was scored from 0 to 5, with 5 being the most likely. Each PFM for each structure was given an LoSF score based on DCR and engineering judgement. DCR is defined as the load demand divided by the available capacity. The DCR was used to quantify the degree of distress of an existing member or connection. DCR values that exceeded 1 were considered to have exceeded their capacity for the evaluated performance level. The LoSF scores assigned to each PFM that do not meet the seismic performance criteria can be seen in the structure-specific tables contained within Appendix H. 6.2 Consequence Descriptions and Weights A CoSF score was given for each PFM to reflect the impact to OCSD, its customers, the environment, and stakeholders should a failure occur. Six consequence criteria were developed. Two criteria were identified specifically for seismic consequences: life safety; and primary treatment and digestion. The other four criteria (regulatory, stakeholder commitments, financial impacts, and public impacts) use OCSD’s levels of service (LOS) and corresponding goals as a guide, as developed for the FMP. Since not all consequences have the same severity, an importance factor was applied to each consequence criterion. Assigned importance factors (IFs) are as follows: • Life Safety, IF=100%; • Primary Treatment and Digestion , IF=100%; • Regulatory, IF=80%; • Stakeholder Commitments, IF=37.5%; • Financial, IF=80%; and • Public Impacts, IF=16.5%. Each consequence is described in the following sections. Additional detail related to the scoring of each consequence is provided in the General Notes contained in Appendix G. 6.2.1 Life Safety This criterion was used to evaluate PFMs on the basis of whether a seismic failure of the facilities and/or components would result in the potential for serious injury or loss of life of OCSD employees, on-site staff, and the public. The person hours per year were used to develop the occupancy of each structure, shown in Tables 6.1 and 6.2 for Plants 1 and 2, respectively. If the facilities and/or components of a project fail under the PFM and threaten life safety due to the likely presence of people at the facility, then that PFM was given a higher score. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 27 7/19/2019 6.2.2 Primary Treatment and Digestion This criterion was used to evaluate PFMs on the basis of whether a failure of the facilities and/or components would result in compromising the ability of OCSD to receive wastewater into the plant and discharge it from the plant with at least a primary level of treatment and/or compromising the ability to provide anaerobic digestion of wastewater solids. If the facilities and/or components of a project fail and directly impact the capability of OCSD to receive and discharge wastewater flow with at least a primary level of treatment, and/or the ability to provide digestion of solids for a longer term, then that PFM was given a higher score. 6.2.3 Regulatory This criterion was primarily used to evaluate PFMs on the basis of whether a failure of the facilities and/or components would result in compromising the ability to meet OCSD LOS goals for spill management, air emissions, secondary treatment standards, effluent water quality, and biosolids reuse. Health and safety of OCSD employees, on-site staff, and the public are also considered under this criterion with respect to Occupational Safety and Health Administration requirements and OCSD-specific safety goals. If the facilities and/or components fail and directly impact the capability of OCSD to meet LOS goals for a longer term, then that PFM was given a higher score (i.e., fails to meet goals). 6.2.4 Stakeholder Commitments This criterion was used to evaluate PFMs on the basis of whether a failure of the facilities and/or components would compromise OCSD’s ability to meet its water quality and flow requirements for Groundwater Replenishment System (GWRS) and any other stakeholder expectations. A higher score was given to those PFMs whose failure results in OCSD not meeting its GWRS or other stakeholder commitments for a longer term. 6.2.5 Financial Impacts This criterion was used to evaluate PFMs on the basis of whether a failure of the facilities and/or components would result in a financial impact to OCSD, including repair or replacement of the facility and increased Operation and Maintenance (O&M) costs. Financial O&M impacts include costs associated with equipment failure, emergency repairs, water loss, claims, or other impacts that are financial in nature. A failure that may result in high repair/replacement costs, major fines, property damage, and/or failure to meet OCSD’s long-term LOS goals for balanced O&M costs was given a higher score. 6.2.6 Public Impacts This criterion was used to evaluate PFMs on the basis of whether a failure of the project facilities and/or components would result in compromising the ability to meet OCSD LOS goals for odor complaints and response time. A higher score was given to those projects yielding an increase in customer odor complaints or response time should its facilities and/or components fail. Also, potential impacts to the public (i.e., street closures, traffic disruption, harbor/beach closures) from HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 28 7/19/2019 collection systems spills was considered under this criterion. A higher score was given to a PFM that had the potential for longer-term collection system spills and subsequent public impact should its facilities and/or components fail. 6.2.7 Summary of OCSD Input Regarding Consequences OCSD established the basis of consequence rankings as part of the 2017 Facility Master Plan (FMP) and participated in modifying these criteria for this study to include life safety and primary treatment and digestion, because these are important seismic consequences. OCSD also reviewed and modified the importance factor for each consequence of seismic failure based on its importance for seismic vulnerabilities. Similarly, OCSD reviewed and provided input on the CoSF ratings for each structure. Ratings were reviewed with OCSD at the December 12, 2018 and January 9, 2019 workshops and adjusted to reflect input received by the participants. 6.3 Calculation of RoSF for each PFM Once PFM’s were identified for each structure at Plant 1 and Plant 2, an RoSF was calculated for each PFM. The score is the product of the LoSF and the CoSF. Each PFM could then be compared with others for the specific structure based on RoSF scores, and the controlling PFM was determined to be the one with the highest RoSF. 6.3.1 BSE-1E vs BSE-2E A preliminary class designation for each structure was determined by OCSD at the Plant 1 and Plant 2 workshops. In general, process facilities were designated Class I, and non-process buildings were designated Class II, with a few exceptions. The required performance requirements for the structures Class designations were established as the following: • Class I: Continued occupancy and operation; and • Class II: Repair or replacement in required for continued occupancy and operation, but gravity load-bearing elements continue to function, and there are no out-of-place wall failures. The seismic hazard levels for structures that were evaluated in this study were established using the ASCE 41-13 standard. For the existing structures that were evaluated, the BSE was used with the performance objectives, shown in Table 2.1 of TM3 (Appendix B). The evaluations of the building and the nonbuilding structures at the plants were performed using two BSE levels: (i) BSE-1E; and (ii) BSE-2E, which are seismic hazard levels with a 20% and 5% probability of exceedance in 50 years, respectively. For ranking the structures by risk, only one BSE level was used per structure. When the two BSE levels of a structure had different scores, the level that had the highest RoSF score was used as the representation of that structure. However, in most cases, both levels 1E and 2E had the same RoSF score. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 29 7/19/2019 6.4 Calculation of Structure RoSF Overall structure RoSF was calculated the same way as RoSF for each PFM. Once all PFM’s were given an RoSF score, the controlling PFM was identified as the one with the highest score. The PFM with the highest score was identified as the controlling PFM. The score of this controlling PFM then became the overall structure RoSF score. 6.4.1 Controlling Failure Type PFMs were classified as either lateral spread, ground shaking, or differential settlement. The controlling failure type for each structure was determined based on the PFM that had the highest RoSF score. The PFM with the highest score governed the failure type for the specific structure as seen in Tables 6.3 and 6.4 for Plants 1 and 2, respectively. 6.4.2 Controlling Consequence The controlling consequence for each structure was also based on the PFM with the highest overall RoSF score and can also be seen in Tables 6.3 and 6.4. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 30 7/19/2019 7. PROJECT RANKING 7.1 Risk Ranking Within Facility Master Plan Framework A primary goal of this study was to develop a prioritized list of Capital Improvement Program (CIP) projects at each plant that addresses seismic vulnerabilities for the evaluated structures. The seismic project ranking system is risk based, and the prioritization approach allows OCSD to integrate the projects into the FMP at the conclusion of this study. This section outlines the approach to develop and prioritize the CIP projects in accordance with these objectives. It also presents for each plant a prioritized listing of the evaluated structures with information about the controlling seismic vulnerabilities, potential consequences of failure, mitigation costs, facility values, and recommendations to address seismic vulnerabilities. Based on the findings of this study, recommendations were made based on several factors, including the highest overall risk of failure score, cost of mitigation compared to facility value, and the potential for mitigating seismic projects within an already planned project 7.1.1 Based on Highest RoSF Score With the completion of both the structural and the geotechnical evaluations of Plant 1 and Plant 2, the risk ranking of structures per plant was developed using the PFM with the highest overall RoSF score. PFMs were identified for each structure and evaluated individually to identify the controlling failure type and controlling consequence. Tables 7.1 and 7.2 show the risk ranking of Plants 1 and 2 according to the RoSF score. Structures at the top of the list are the ones that have the highest priority based on risk. The structures at the bottom of the table with a score of zero are structures that were judged not likely to fail at the designated seismic hazard levels. 7.1.2 Structures That Can Be Mitigated Using an Already Planned Project In the FMP, there are many structures that are recommended to undergo rehabilitation or replacement to achieve the goals of the FMP. Some of these projects include structures that were identified in the seismic study. Tables 7.1 and 7.2 show the structures that could be addressed as part of a previously proposed project. 7.1.3 Structures Subject to Lateral Spread At Plant 1, there are several structures that include a PFM with a lateral spread failure type. To mitigate these PFMs, the lateral spread impacts to the structure should be addressed. At Plant 1, for practical reasons, instead of addressing lateral spread on a structure-by-structure basis, Table 7.1 indicates a recommendation to mitigate the entire plant frontage (see alignment identified in TM3 Figure 7.1). The approximate total cost to mitigate lateral spread of Plant 1 would be between $50M and $150M with a best estimate of $100M. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 31 7/19/2019 At Plant 2, the team identified and prepared cost estimates for lateral spread mitigation that address vulnerabilities at the subject structures (see alignment identified in TM3 Figure 7.2). The approximate total cost to mitigate lateral spread at the subject structures at Plant 2 would be from approximately $25M to $75M, with a best estimate of approximately $50M. A lateral spread mitigation for the entire Plant 2 river and marsh frontage is estimated to cost approximately $125M to $350M with a best estimate of $225M. 7.2 Plant 1 Recommended Project Prioritization This section provides a discussion of selected structures at Plant 1 to illustrate the prioritization process. 7.2.1 1-8 Control Center For the Control Center at Plant 1, a total of seven PFMs were identified and categorized by failure type. Each of the seven PFMs was given a DCR score and a corresponding LoSF score. Additionally, each PFM was given a score for each of the six consequences described in Section 6 and weighted accordingly. For the Control Center, PFMs 2, 3, and 6 had the highest LoSF score of 5. These PFMs are the controlling failure modes for the structure. The failure type that corresponds with those PFMs and ground shaking is the controlling failure type for the structure. Next, the occupancy and impact that a seismic event would have on the structure was examined to score the PFMs for the consequences described in Section 6. Because the Control Center has a high occupancy value, the highest CoSF score for each PFM was given in the life safety category, making life safety the controlling consequence of the Control Center. The RoSF score for each PFM was calculated by multiplying the CoSF and LoSF score together. The PFMs with the highest RoSF score control the overall RoSF score for the structure. The RoSF score for the Control Center is 25, the highest possible score. For the PFMs identified, mitigation methods were proposed and a cost was estimated, as described in Section 5. The cost to mitigate the Control Center was then developed based on the total of all PFMs. For the Control Center, the total cost to mitigate the structure is $7.2 million; while the facility value, determined for the 2017 FMP, is about $16 million. Because the seismic risk is high and the cost to mitigate is low compared to the value of the facility, mitigation is recommended to address seismic risk. 7.2.2 1-9 12-kV Service Center The 12-kV Service Center in Plant 1 also has a high overall RoSF score of 25. The basis of developing scores followed the procedure described above, but a higher CoSF score was given to primary treatment rather than life safety. This was because the 12-kV Service Center functions to provide power to the entire plant, which could greatly affect OCSD’s ability to provide primary treatment. Therefore, this consequence was given the highest value. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 32 7/19/2019 From the two PFMs identified, PFM 2 had the highest DCR and LoSF score, so the corresponding PFM failure type, ground shaking, was controlling for the structure. Additionally, the cost for mitigation of the 12-kV service center is $0.23 million, much lower than the facility value of $42.1 million. Since there is currently no planned project that would address the seismic risk of this building, OCSD should consider mitigation through a new planned project. 7.2.3 1-31 Buildings 5 and 6 Buildings 5 and 6 were evaluated and scored in a similar manner, producing a high RoSF score. For the three PFMs identified, PFM 6 was the governing failure mode with a corresponding ground shaking failure type, and life safety as the governing consequence because of the high occupancy of the structure. The facility value, $4.9 million, compared to the cost to mitigate, $1.26 million, combined with the high RoSF score of 25, led to the recommendation for mitigating the structure with a new project. 7.2.4 1-34 Laboratory Complex The Laboratory Complex was evaluated and scored, giving it a high overall RoSF score of 25. Of the six PFM’s identified, four had an RoSF score of 25, making them all governing PFMs. All had ground shaking failure type and all were dominated by life safety as the controlling consequence. This structure is valued at $22.8 million compared to the cost to mitigate of $5.1 million. Life safety consequences make the Laboratory Complex a priority recommendation for mitigation with a new project. 7.3 Plant 2 Recommended Project Prioritization This section provides a discussion of selected structures at Plant 2 to further illustrate the prioritization process. 7.3.1 2-23 Surge Tower No. 1 When Surge Tower No. 1 was evaluated, two PFM’s were identified, both due to lateral spread. Both PFMs had a DCR score greater than 1, and PFM 10 was given the highest LoSF score. Further evaluation gave the highest CoSF score to primary treatment and regulatory, but with the weightings described in Section 6, primary treatment is the controlling consequence. Since all PFMs in Surge Tower No. 1 were caused by lateral spread, the total cost to mitigate this structure was included within the overall lateral spread mitigation costs for the plant. 7.3.2 2-27 Maintenance Building The Maintenance Building at Plant 2 is a highly occupied building, so the controlling consequence is life safety, leading to the highest scoring for each identified PFM to be in this category. Of the nine PFM’s identified, four contributed to the overall RoSF score of 25 and all had the governing failure mode of ground shaking. The cost of mitigation is $18.7 million, compared to the facility HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 33 7/19/2019 value of $9.5 million. Because the mitigation cost is high, OCSD may consider complete replacement as an alternative to mitigation 7.3.3 2-29 Ocean Outfall Booster Pump Station The Ocean Outfall Booster Pump Station had four different PFMs identified, all affecting primary treatment, regulatory, and financial impacts. PFMs that had a 5 as an LoSF score all had the governing failure mode as ground shaking and with the weightings described in Section 6. Primary treatment was the controlling consequence. 7.4 Integration with the Facility Master Plan (FMP) The risk ranking of the seismic projects is useful for prioritizing seismic projects compared to the other seismic projects. However, these risk rankings are not conducive to FMP integration, because design-level seismic events are much less predictable and have very low occurrence probabilities compared to non-seismic Likelihood of Failure (LoF) factors, such as deterioration due to age. LoF based on seismic probability is not meaningful, so another approach is needed for integration. Although integration with the FMP was not included within the scope of this seismic study, the following discussion describes how OCSD could perform such an integration, if needed. 7.4.1 Overview of FMP Prioritization An overview of the FMP prioritization process is useful to explain how the approach to prioritizing seismic projects will allow OCSD to integrate the projects into the FMP at the conclusion of this study. The 2017 FMP projects were prioritized using a four-step approach as shown in the green boxes of Figure 7.1 and as outlined below. Step 1: Projects were sorted by LoF/Remaining Useful Life. Typically, a facility that needed a project was evaluated to determine the year that it would reach its end of life, assuming that no project was implemented to extend its life. In most cases, the Step 1 evaluation alone established the necessary prioritization because OCSD proactively plans projects to prevent nearly all facilities from reaching their estimated end of life. A facility would reach its end of life due to one of the following failure modes: • Condition; • Capacity; • Redundancy; • Regulations; • Initiative; • Seismic (not used); and • Health and Safety. Step 2: Projects were then evaluated and modified as necessary to comply with the sequencing constraints and overall feasibility. This step adjusted project schedules to avoid construction HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 34 7/19/2019 sequencing issues, capacity shortfalls, and site conflicts, etc. Some projects needed to be deferred or accelerated to address coordination constraints. Step 3: OCSD analyzed cash flow/resource requirements for the projects, as scheduled by Steps 1 and 2. Then, cash flow/resources were leveled by proposed schedule shifts for selected projects. Step 4: The Consequence of Failure (CoF) was evaluated for each project to rank the importance of maintaining a schedule that would avoid the end of life for that facility. Four consequences, each with a “weighted” importance factor (IF), were evaluated for each project, as follows: • Regulatory, IF=100%; • Stakeholder Commitments, IF=75%; • Financial, IF=50%; and • Public Impacts, IF=33%. The highest score for each consequence governed the CoF score. (Scores for separate consequences were not additive). Overall Risk of Failure (RoF) was then calculated as the product of LoF scores and CoF scores. Generally, CoF scores were used to propose and verify that Step 2 and Step 3 schedule adjustments were made in such a way as to minimize risk. RoF scores were used as a final check on the proposed CIP. 7.4.2 Approach to Integration with the FMP The approach for integration with OCSD’s FMP is shown in the blue boxes of the flowchart in Figure 7.1. This approach uses a strategic initiative-based determination of LoF based on the Consequences of Seismic Event (CoSE). The initiative-based approach is intended to allow OCSD stakeholders to customize the criteria that trigger a seismic project to match OCSD’s goals and budget. The graphic shows the proposed strategic initiative that would be used for this determination 7.4.3 Proposed Initiative for CoSE The CoSE initiative evaluates the importance of seismic mitigation projects. These seismic consequences are similar to those used for the CoF of non-seismic projects, but are more appropriate for failures resulting from a natural disaster. In particular, consideration of life safety and the duration of consequences are much more important for seismic failures. Accordingly, a facility with a CoSE that threatens life safety may have an LoF score of “5,” meaning a project to address this threat should be implemented within 0 to 5 years. A facility with a CoSE that threatens OCSD’s primary treatment/digestion capabilities – the ability to receive wastewater into the plant and discharge it from the plant with at least a primary level of treatment, and/or compromising the ability to provide anaerobic digestion of wastewater solids – would have an LoF score of “4,” meaning a project to address this threat should be implemented within 5 to 10 years. Following a major earthquake, it may be acceptable to operate under conditions that would result in regulatory violations for a short duration. However, to avoid long-term violations, OCSD may HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 35 7/19/2019 choose to implement measures of seismic resiliency. The proposed initiative could provide an LoF score of “3” for regulatory violations, meaning a project to avoid these impacts should be implemented within the next 10 to 15 years. Likewise, following a major earthquake, OCSD may choose to use emergency funding from outside agencies that can provide a cost-effective means of addressing disaster needs if the cost of full seismic resiliency exceeds available budget. This strategy could reduce the financial impact of seismic projects, and the proposed initiative could provide an LoF score of “3,” meaning a project should be implemented in the next 10 to 15 years. 7.4.4 Remaining Integration Steps With the CoSE initiative defined, the next step is to review how the seismic projects impact, or are impacted by, the non-seismic projects in the FMP. This step is similar to Step 2 that was performed for the FMP projects. Projects should be evaluated and modified as necessary to comply with sequencing constraints, site conflicts, and overall feasibility. In many cases, it may make sense to address seismic vulnerabilities for a structure when a project for that facility is being implemented to address other issues. In addition, projects should be reviewed to determine the need for an evaluation for “mitigate vs. replace,” since combinations of projects or repackaged projects may impact previous decisions on the most appropriate planning strategy. The next step is to update LoF for all projects that have been added or modified by the seismic projects. This step will include confirmation of the CoSE initiative scoring for seismic projects and LoF evaluations for projects that have both seismic and non-seismic elements. Once this update has been completed, the LoF scoring for all projects, both seismic and non-seismic, will be on the same basis and suitable for input into the four-step FMP prioritization process described in Section 7.4.1. All CIP projects would then be processed though the FMP process. This involves some re-processing of the non-seismic projects that were prioritized during the 2017 FMP projects, as well as adding the seismic projects. Step 3 of the FMP process performs cash flow/resource leveling. At this stage, the schedule for seismic projects may need to be modified to achieve resource leveling. To decide/confirm that schedule changes are acceptable, CoF should be reviewed and projects rescheduled to achieve both resource leveling and overall risk minimization. As shown in the flowchart, the CoF for seismic projects, which allows calculation of the final risk score, is based on complying with the stakeholder commitments, not the CoSE. This is an important distinction, because the use of CoF as this step, instead of CoSE, puts the risk scoring on the same basis as the non-seismic projects, potentially avoiding over-emphasis of seismic projects. Finally, as performed for the FMP, RoF scores should be used as a final check on the proposed CIP. With this step completed, the seismic projects will be fully integrated into the overall CIP. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 36 7/19/2019 8. SUMMARY This final report of the PS15-06 study presents the results of seismic evaluations of a subset of structures at the Plant 1 and Plant 2 sites. These evaluations identified a number of significant vulnerabilities to the subject structures at each plant site. These vulnerabilities are driven by strong ground shaking, liquefaction-induced settlement, and lateral spreading. They have the potential to impact life safety, the ability to provide primary treatment, and the ability to meet regulatory commitments, and they may pose future financial impacts to OCSD. To address these identified vulnerabilities and meet OCSD’s performance objectives, conceptual retrofit recommendations were developed along with planning-level cost estimates. This study identifies a total of approximately $136 million in recommended retrofit projects at Plant 1 and a total of $209 million in recommended retrofit projects at Plant 2. Working with OCSD, a process was developed to prioritize and provide relative rankings for implementation of these retrofit measures. Based on this process, the study recommends implementation of these projects with the priority identified in Table 7.1 and Table 7.2 of this report. The implementation of these seismic-related projects will require an integration with OCSD’s non-seismic Capital Improvement Program. A potential strategy for this integration is proposed in this report. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 37 7/19/2019 9. REFERENCES American Concrete Institute (ACI) [2006]. “Code Requirements for Environmental Engineering Concrete Structures.” ACI Committee 350. American Petroleum Institute (API) [2011]. “Welded Tanks for Oil Storage.” API, Washington, DC, USA. American Society of Civil Engineers (ASCE)/Structural Engineering Institute (SEI) Standard 7- 10 [2010]. “Minimum Design Loads for Buildings and Other Structures.” ASCE, Reston, VA, USA. ASCE/SEI Standard 41-13 [2014]. “Seismic Evaluation and Retrofit of Existing Structures.” ASCE, Reston, VA, USA. Kleinfelder [2017]. “Fault Displacement Hazard Analysis Report, OCSD Plant No. 2.” OCSD Project No. P2-98, 6 November 2017. HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 7/19/2019 TABLES Table 4.1 Standard Structural Mitigation Table OCSD PS15-06 Orange County, California ID Mitigation Name Description A1 Wall Anchorage Type 1 Provide steel angles or WT struts with steel hardware and epoxy bonded anchors into the existing wall or perimeter roof beam at 8 feet on center. Struts to extend into the diaphragm as required to develop the wall anchorage force. Struts are to be field welded to the roof deck. A2 Wall Anchorage Type 2 Provide new steel welded or bolted connections to existing beams that are epoxy bonded to the existing wall, pilaster, or perimeter concrete beam. Mitigation includes additional roof deck welding as required for full wall anchorage force development into the diaphragm. The scope of work is expressed as High, Medium, and Low. B1 Roof Diaphragm Strengthening Type 1 Replace existing roof deck to the extent the deck is deficient and provide supplemental steel roof framing as required. B2 Roof Diaphragm Strengthening Type 2 Provide additional epoxy bonded anchors at the existing ledger angle. Drill anchors through the existing ledger angle and embed into the existing concrete or masonry walls. C1 Foundation Tie Type 1 Provide steel angle tie plate that is anchored into the wall and slab at the interior of the building using epoxy bonded anchors. Angles are assumed to be required at a spacing of 4 feet on center. C2 Foundation Tie Type 2 Provide an exterior cast-in-place concrete tie beam that is cast at the exterior of the building below grade and doweled into the existing wall and footings (continuous or isolated pad footings) with an epoxy adhesive. D OOP Wall Bracing Provide vertical steel tube or steel channel members to reduce the horizontal span of the wall, especially where pilasters occur. The vertical member is to be anchored to the masonry or concrete wall with epoxy bonded anchors regularly spaced. The vertical member is required to be braced to the foundation and to the roof framing with additional hardware and framing members as required. E Cast-in-place Concrete Infill Infill existing window with cast-in-place concrete. Install reinforcing steel dowels into existing wall, beam, and columns at the perimeter of the existing window using an epoxy adhesive. Table 4.2 Standard Geotechnical Mitigation Table OCSD PS15-06 Orange County, California ID Mitigation Name Description A1 Ground Improvement Buttress Construct a cemented mass of in-situ soil (by deep soil mixing, jet grouting, or similar method) between the structure and the Santa Ana River and/or Talbert Marsh, as applicable. A2 Secant Pile Wall Construct a secant pile wall comprised of closely-spaced steel pipe piles filled reinforced concrete to resist liquefaction-induced lateral spreading towards the Santa Ana River and/or Talbert Marsh. B1 Ground Improvement Under Slab Foundation Use one of several available ground improvement techniques to reduce the liquefaction potential of specified soil strata beneath the footprint of the entire structure. B2 Ground Improvement Under Perimeter Footings Use one of several available ground improvement techniques to reduce the liquefaction potential of a specified strata of soil directly beneath the structure footings. C Ground Improvement Around Perimeter of Submerged Walls Treat the soils immediately outside basement walls, using one of several available ground improvement techniques, to limit liquefaction in soil backfill and reduce the potential for increased lateral earth pressure on submerged walls. Table 5.1. Facility Values, Plant 1 OCSD PS15-06 Orange County, California Structure Number Structure Name Value(1) 1 Waste Sludge Thickeners (DAFT) Pump Room $4,000,000 2 Blower Building (AS1) and PEPS $109,668,000 3 Plant Water Pump Station and Power Building 6 $6,760,000 4 City Water Pump Station $5,030,000 5 Power Building 2 $6,236,000 6 Power Building 4 $5,382,000 7 Power Building 5 $10,841,000 8 Control Center $16,200,000 9 12 kV Service Center $42,100,000 10 Central Power Generation Building $154,800,000 11 Aeration Basins 1‐10 $219,336,000 12 Secondary Clarifiers 1‐26 $219,336,000 13 Digester 5 $10,150,000 14 Digester 5 & 6 Pump Room $6,764,000 15 Digester 6 $10,150,000 16 Digester 7 $10,150,000 17 Digester 7 & 8 Pump Room $6,764,000 18 Digester 8 $10,150,000 19 Digester 9‐10 $22,000,000 20 Digester 9‐10 Pump Room $7,322,000 21 Digesters 11‐16 $66,000,000 22 Digesters 11‐14 Pump Room $14,650,000 23 Digesters 15‐16 Pump Room $7,322,000 24 Gas Holder $454,000 25 Effluent Junction Box $2,012,000 26 Solids Storage Facility $29,540,000 27 Chiller Building $682,000 28 Warehouse Building $2,739,000 29 Shop Building A $1,956,000 30 Shop Building B and Building 3 $4,230,000 31 Buildings 5 and 6 $4,893,000 32 Auto Shop $1,853,000 33 PEDB2 $4,585,000 34 Central Laboratory $22,840,000 Plant No. 1 (1) Generally taken from Facilities Valuation Report 2017 under Project PS15‐10, where information was not available from this source, very approximate estimates of value were used (note that the analysis only requires identification of the financial ranking) Table 5.2. Facility Values, Plant 2 OCSD PS15-06 Orange County, California Structure Number Structure Name Value (1) 1 DAFT A‐C Gallery $5,444,000 2 DAFT D Gallery and WSSPS $3,629,000 3 RAS PS East $27,804,000 4 RAS PS West $27,804,000 5 PEPS & MAC $55,609,000 6 Operations/Control Center $21,312,000 7 12 kV Service Center $42,100,000 8 Power Building B $5,063,000 9 Power Building C $4,361,000 10 Power Building D $3,947,000 11 City Water Pump Station $8,629,000 12 12 kV Distribution Center B $9,686,000 13 12 kV Distribution Center D $2,520,000 14 Headworks Power Bldg A $5,063,000 15 Headworks Power Bldg B $5,063,000 15 Headworks Power Bldg B $5,063,000 16 Headworks Standby Power Building $5,972,000 16 Headworks Standby Power Building $5,972,000 17 Central Power Generation Building $330,240,000 17 Central Power Generation Building $330,240,000 18 Aeration Basins A‐H $222,436,000 18 Aeration Basins A‐H $222,436,000 19 Gas Holder $600,000 19 Gas Holder $600,000 20 Secondary Clarifiers A‐L $222,436,000 20 Secondary Clarifiers A‐L $222,436,000 21 DAFTs A‐C $16,333,000 21 DAFTs A‐C $16,333,000 22 DAFT D $3,630,000 23 Surge Tower No. 1 $18,300,000 24 Surge Tower No. 2 $18,300,000 26 Truck Loading $27,300,000 27 Maintenance Building $9,489,000 28 Boiler Building $2,000,000 29 Ocean Outfall Booster Pump Station $109,650,000 30 12 kV Distribution Center A $8,717,000 Plant No. 2 (1) Generally taken from Facilities Valuation Report 2017 under Project PS15‐10, where information was not available from this source very approximate estimates of value were used (note that the analysis only requires identification of the financial ranking) Table 6.1. Sturcture Occupancy, Plant 1 OCSD PS15-06 Orange County, California Occupancy Hours per Year Structure Number Structure Name Electrical and Instrumentation Maintenance Total(1) Life Safety Rating 1 Waste Sludge Thickeners (DAFT) Pump Room 1500 2500 4,000 3 2 Blower Building (AS1) and PEPS 750 750 2,000‐10,000 3 3 Plant Water Pump Station and Power Building 6 500 250 <2,000 2 4 City Water Pump Station 100 100 <2,000 2 5 Power Building 2 200 400 <2,000 2 6 Power Building 4 200 400 <2,000 2 7 Power Building 5 200 400 <2,000 2 8 Control Center >20,000 5 9 12 kV Service Center 250 0 <2,000 2 10 Central Power Generation Building 6000 6,000 3 11 Aeration Basins 1‐10 100 250 <2,000 2 12 Secondary Clarifiers 1‐26 200 500 <2,000 2 13 Digester 5 <2000 2 14 Digester 5 & 6 Pump Room <2000 2 15 Digester 6 <2000 2 16 Digester 7 <2000 2 17 Digester 7 & 8 Pump Room <2000 2 18 Digester 8 <2000 2 19 Digester 9‐10 <2000 2 20 Digester 9‐10 Pump Room <2000 2 21 Digesters 11‐16 <2000 2 22 Digesters 11‐14 Pump Room <2000 2 23 Digesters 15‐16 Pump Room <2000 2 24 Gas Holder <2000 2 25 Effluent Junction Box <2000 2 26 Solids Storage Facility 3,650 3 27 Chiller Building <2000 2 28 Warehouse Building 30,000 5 29 Shop Building A 10,000 4 30 Shop Building B and Building 3 14,000 4 31 Buildings 5 and 6 100,000 5 32 Auto Shop 10,000‐20,000 4 33 PEDB2 0 2 34 Central Laboratory >20000 5 (1) Compiled from various sources of data supplied by OCSD Plant No. 1 Table 6.2. Structure Occupancy, Plant 2 OCSD PS15-06 Orange County, California Occupancy Hours per Year Structure Number Structure Name Electrical and Instrumentation Maintenance Total Hours Life Safety Rating 1 DAFT A‐C Gallery 3,000 3 2 DAFT D Gallery and WSSPS 1,100 2 3 RAS PS East 1,100 2 4 RAS PS West 1,100 2 5 PEPS & MAC 400 2 6 Operations/Control Center 8,760 4 7 12 kV Service Center <2,000 2 8 Power Building B 730 2 9 Power Building C 400 2 10 Power Building D 730 2 11 City Water Pump Station <2,000 2 12 12 kV Distribution Center B <2,000 2 13 12 kV Distribution Center D <2,000 2 14 Headworks Power Bldg A 730 2 15 Headworks Power Bldg B 730 2 15 Headworks Power Bldg B 730 2 16 Headworks Standby Power Building 730 2 16 Headworks Standby Power Building 730 2 17 Central Power Generation Building 2,000‐10,000 3 17 Central Power Generation Building 2,000‐10,000 3 18 Aeration Basins A‐H 3,650 3 18 Aeration Basins A‐H 3,650 3 19 Gas Holder 400 2 19 Gas Holder 400 2 20 Secondary Clarifiers A‐L 3,650 3 20 Secondary Clarifiers A‐L 3,650 3 21 DAFTs A‐C 3,000 3 21 DAFTs A‐C 3,000 3 22 DAFT D 3,000 3 23 Surge Tower No. 1 <2,000 2 24 Surge Tower No. 2 <2,000 2 26 Truck Loading 3,650 3 27 Maintenance Building >20,000 5 28 Boiler Building 1,600 2 29 Ocean Outfall Booster Pump Station <2,000 2 30 12 kV Distribution Center A <2,000 2 (1) Compiled from various sources of data supplied by OCSD Plant No. 2 Table 6.3. Controlling Failure Type and Controlling Consequence, Plant 1 OCSD PS15-06 Orange County, California Plant 1 Structure Number Structure Name GS DS LS Li f e S a f e t y Pr i m a r y Tr e a t m e n t Re g u l a t o r y St a k e h o l d e r Fi n a n c i a l Pu b l i c I m p a c t 1 Waste Sludge Thickeners (DAFT) Pump Room x x x 2 Blower Building (AS1) and PEPS x x x 3 Plant Water Pump Station & Power Building 6 x xx 4 City Water Pump Station x x x 5 Power Building 2 xxxx 6 Power Building 4 x x 7 Power Building 5 x x 8 Control Center x x 9 12 kV Service Center x x 10 Central Power Generation Building x x 11 Aeration Basins 1‐10 x x x 12 Secondary Clarifiers 1‐26 x x x 13 Digester 5 x x 14 Digester 5 & 6 Pump Room x x x 15 Digester 6 x x 16 Digester 7 x x 17 Digester 7 & 8 Pump Room x x x 18 Digester 8 x x 19 Digester 9‐10 x x 20 Digester 9‐10 Pump Room x x x 21 Digesters 11‐16 x x 22 Digesters 11‐14 Pump Room x x x 23 Digesters 15‐16 Pump Room x x 24 Gas Holder x x 25 Effluent Junction Box x x 26 Solids Storage Facility xx 27 Chiller Building x x x 28 Warehouse Building x x x 29 Shop Building A x x 30 Shop Building B and Building 3 x x 31 Buildings 5 and 6 x x 32 Auto Shop x x 33 PEDB2 x x 34 Central Laboratory x x Control. Failure Controlling Consequence Table 6.4. Controlling Failure Type and Controlling Consequence, Plant 2 OCSD PS15-06 Orange County, California Structure Number Structure Name Hazard Level GS DS LS Li f e S a f e t y Pr i m a r y Tr e a t m e n t Re g u l a t o r y St a k e h o l d e r Fi n a n c i a l Pu b l i c I m p a c t 1 DAFT A‐C Gallery 1E x x 2 DAFT D Gallery and WSSPS 1E x x 3 RAS PS East 2E x x x 4 RAS PS West 2E x x x 5 PEPS & MAC 1E x x 6 Operations/Control Center 1E x x 7 12 kV Service Center 1E x x 8 Power Building B 1E x x 9 Power Building C 1E x x 10 Power Building D 1E x x 11 City Water Pump Station 1E x x 12 12 kV Distribution Center B 1E x x 13 12 kV Distribution Center D 1E x x 14 Headworks Power Bldg A 1E x x 15 Headworks Power Bldg B 1E x x 16 Headworks Standby Power Building 1E x x 17 Central Power Generation Building 1E x x 18 Aeration Basins A‐H 1E x x x 19 Gas Holder 1E x x 20 Secondary Clarifiers A‐L 1E x x x 21 DAFTs A‐C 1E x x 22 DAFT D 1E x x x 23 Surge Tower No. 1 1E x x 24 Surge Tower No. 2 1E x x 26 Truck Loading 2E x x 27 Maintenance Building 1E x x 28 Boiler Building 1E x x 29 Ocean Outfall Booster Pump Station 1E x x 30 12 kV Distribution Center A 1E x x Plant 2 ‐ Risk Ranking Control. Failure Controlling Consequence Table 7.1 Prioritized List of Recommended Mitigations with Costs, Plant 1 OCSD PS15-06 Orange County, California Plant 1 ‐ Risk Ranking Structure Number Structure Name GS DS LS Li f e S a f e t y Pr i m a r y T r t m t , Di g e s t i o n Re g u l a t o r y St a k e h o l d e r Fi n a n c i a l Pu b l i c I m p a c t Overall RoSF Structural Mitigation Cost Geotechnical Mitigation Cost2 Total Mitigation Cost Facility Value3 No Project, LoSF = 0 Address with Previously Planned Project Mitigate with New Project Identified in TM3 Replace Facility Comments 8 Control Center x x 25 $6,610,000 $0 $6,610,000 $16,200,000 X 9 12 kV Service Center x x 25 $220,000 $0 $220,000 $42,100,000 X 31 Buildings 5 and 6 x x 25 $1,260,000 $0 $1,260,000 $4,893,000 X 34 Central Laboratory x x 25 $5,130,000 $0 $5,130,000 $22,840,000 X 2 Blower Building (AS1) and PEPS x x x 20 $2,440,000 $0 $2,440,000 $109,668,000 X‐048 10 Central Power Generation Building x x 20 $2,280,000 $2,130,000 $4,410,000 $154,800,000 P1‐1274 12 Secondary Clarifiers 1‐26 x x x 20 $0 $0 $0 $219,336,000 X‐049 19 Digester 9‐10 x x 20 $0 $0 $0 $22,000,000 X4 21 Digesters 11‐16 5 x x 20 $0 $0 $0 $66,000,000 X4 30 Shop Building B and Building 3 x x 20 $440,000 $0 $440,000 $4,230,000 X 32 Auto Shop x x 20 $410,000 $0 $410,000 $1,853,000 X 1 Waste Sludge Thickeners (DAFT) Pump Room x x x 15 $840,000 $0 $840,000 $4,000,000 X‐0434 X‐043 will demolish DAFT's; electrical room and lab will stay in place. 26 Solids Storage Facility xx 15 $60,000 $0 $60,000 $29,540,000 X4 28 Warehouse Building x x x 15 $690,000 $0 $690,000 $2,739,000 X 16 Digester 7 x x 12 $0 $0 $0 $10,150,000 X4 18 Digester 8 x x 12 $0 $0 $0 $10,150,000 X4 29 Shop Building A x x 12 $280,000 $0 $280,000 $1,956,000 X 3 Plant Water Pump Station & Power Building 6 x xx 10 $420,000 $0 $420,000 $6,760,000 X‐0394 4 City Water Pump Station x x x 10 $590,000 $1,200,000 $1,790,000 $5,030,000 X‐0384 7 Power Building 5 x x 10 $220,000 $1,170,000 $1,390,000 $10,841,000 J‐124 22 Digesters 11‐14 Pump Room x x x 10 $1,080,000 $0 $1,080,000 $14,650,000 X4 23 Digesters 15‐16 Pump Room x x 10 $420,000 $0 $420,000 $7,322,000 X4 25 Effluent Junction Box x x 10 $0 $0 $0 $2,012,000 X4 33 PEDB2 x x 10 $0 $840,000 $840,000 $4,585,000 X 6 Power Building 4 x x 8 $270,000 $0 $270,000 $5,382,000 X 5 Power Building 2 xxxx 6 $390,000 $2,790,000 $3,180,000 $6,236,000 X4 14 Digester 5 & 6 Pump Room x x x 6 $200,000 $1,420,000 $1,620,000 $6,764,000 X 17 Digester 7 & 8 Pump Room x x x 6 $250,000 $0 $250,000 $6,764,000 X4 20 Digester 9‐10 Pump Room x x x 6 $340,000 $0 $340,000 $7,322,000 X4 24 Gas Holder x x 2.4 $0 $1,800,000 $1,800,000 $454,000 J‐124 11 Aeration Basins 1‐10 0 $0 $0 $0 $219,336,000 X 13 Digester 5 0 $0 $0 $0 $10,150,000 X 15 Digester 6 0 $0 $0 $0 $10,150,000 X 27 Chiller Building 0 $0 $0 $0 $682,000 X Subtotal $24,840,000 $11,350,000 $36,190,000 $1,046,895,000 Plant‐wide LS mitigation NA $100,000,000 $100,000,000 NA Notes:Total $24,840,000 $111,350,000 $136,190,000 $1,046,895,000 1. Mitigation costs are construction costs in Nov 2018 dollars, ENRLA 12006. These costs do not include "soft" project costs. 2. Structure‐specific geotechnical mitigation costs do not include lateral spread mitigation costs. 3. Facility values are approximate values of existing facilities as identified for the 2017 Facility Master Plan. 4. Requires lateral spread (LS) mitigation. Total LS mitigation cost for Plant 1 is $100M. 5. The lateral spread for Digesters 11 and 12 would be less than Digesters 13‐16, resulting in a reduced risk score of 12 for Digesters 11 and 12 if they were evaluated separately. Control. Failure RecommendationsCost Information1 Controlling Consequence Table 7.2 Prioritized List of Recommended Mitigations with Costs, Plant 2 OCSD PS15-06 Orange County, California Structure Number Structure Name GS DS LS Li f e S a f e t y Pr i m a r y T r t m t , Di g e s t i o n Re g u l a t o r y St a k e h o l d e r Fi n a n c i a l Pu b l i c I m p a c t Overall RoSF Structural Mitigation Cost Geotechnical Mitigation Cost2 Total Mitigation Cost Facility Value3 No Project, LoSF = 0 Address with Previously Planned Project Mitigate with New Project Identified in TM3 Replace Facility Comments 23 Surge Tower No. 1 x x 25 $0 $0 $0 $18,300,000 X4 27 Maintenance Building x x 25 $3,430,000 $15,300,000 $18,730,000 $9,489,000 X 29 Ocean Outfall Booster Pump Station x x 25 $2,500,000 $8,230,000 $10,730,000 $109,650,000 X 5 PEPS & MAC x x 20 $0 $7,600,000 $7,600,000 $55,609,000 X‐0524 6 Operations/Control Center x x 20 $2,090,000 $6,780,000 $8,870,000 $21,312,000 X‐008 7 12 kV Service Center x x 20 $780,000 $2,300,000 $3,080,000 $42,100,000 X‐047 8 Power Building B x x 20 $210,000 $0 $210,000 $5,063,000 X 17 Central Power Generation Building x x 20 $3,890,000 $0 $3,890,000 $330,240,000 P2‐119 Project P2‐119 may be cancelled 18 Aeration Basins A‐H x x x 20 $0 $28,400,000 $28,400,000 $222,436,000 X‐050 21 DAFTs A‐C x x 15 $0 $4,970,000 $4,970,000 $16,333,000 X 22 DAFT D x x x 15 $110,000 $1,940,000 $2,050,000 $3,630,000 X 24 Surge Tower No. 2 x x 15 $0 $0 $0 $18,300,000 X4 20 Secondary Clarifiers A‐L x x x 12 $0 $30,240,000 $30,240,000 $222,436,000 X‐051 9 Power Building C x x 10 $280,000 $2,500,000 $2,780,000 $4,361,000 P2‐1194 Project P2‐119 may be cancelled 10 Power Building D x x 10 $670,000 $0 $670,000 $3,947,000 X 14 Headworks Power Bldg A x x 10 $60,000 $2,150,000 $2,210,000 $5,063,000 P2‐98C 28 Boiler Building x x 10 $250,000 $0 $250,000 $2,000,000 X 30 12 kV Distribution Center A x x 10 $670,000 $4,000,000 $4,670,000 $8,717,000 X‐037 To be demolished by Project X‐037 3 RAS PS East x x x 9.6 $180,000 $1,800,000 $1,980,000 $27,804,000 X‐0524 4 RAS PS West x x x 9.6 $180,000 $3,330,000 $3,510,000 $27,804,000 X‐052 1 DAFT A‐C Gallery x x 9 $0 $5,160,000 $5,160,000 $5,444,000 X 11 City Water Pump Station x x 8 $740,000 $4,040,000 $4,780,000 $8,629,000 X‐036 13 12 kV Distribution Center D x x 8 $0 $1,500,000 $1,500,000 $2,520,000 X 15 Headworks Power Bldg B x x 8 $130,000 $2,400,000 $2,530,000 $5,063,000 X 16 Headworks Standby Power Building x x 8 $130,000 $2,970,000 $3,100,000 $5,972,000 X 2 DAFT D Gallery and WSSPS x x 6 $0 $0 $0 $3,629,000 X4 12 12 kV Distribution Center B x x 6 $0 $5,170,000 $5,170,000 $9,686,000 X4 19 Gas Holder x x 2.4 $0 $2,300,000 $2,300,000 $600,000 J‐124 26 Truck Loading 0 $0 $0 $0 $27,300,000 X Subtotal $16,300,000 $143,080,000 $159,380,000 $1,223,437,000 LS Mitigation to Address PS15‐06 Structures Only NA $50,000,000 $50,000,000 NA Total $16,300,000 $193,080,000 $209,380,000 $1,223,437,000 Subtotal $16,300,000 $143,080,000 $159,380,000 $1,223,437,000 Plant‐wide LS Mitigation NA $225,000,000 $225,000,000 NA Notes:Total $16,300,000 $368,080,000 $384,380,000 $1,223,437,000 1. Mitigation costs are construction costs in Nov 2018 dollars, ENRLA 12006. These costs do not include "soft" project costs. 2. Structure‐specific geotechnical mitigation costs do not include lateral spread mitigation costs. 3. Facility values are approximate values of existing facilities as identified for the 2017 Facility Master Plan. 4. Requires lateral spread (LS) mitigation. Total LS mitigation cost for Plant 2 structures included in study is $50M. Total LS mitigation cost for entire Plant 2 river and marsh frontage is $225M. Recommendations Control. Failure Controlling Consequence Plant 2 ‐ Risk Ranking Cost Information1 HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 7/19/2019 FIGURES PROJECT APPROACH FLOWCHART OCSD PS15-06ORANGE COUNTY, CALIFORNIA Figure 1.1 Project No: HL1635 JULY 2019 OC S D -11 x 1 7 N L 4 -Wi t h o u t S c a l e a n d N o r t h A r r o w . d o c Task 1 Task 2/Task 3 Task 3 Task 4 OCSD Seismic Evaluations Geotechnical Investigations and Evaluations Geotechnical Mitigation Measures and Costs Document Reviews and Site Visits Structural Evaluations Structural Mitigation Measures and Costs Risk Based Prioritization Seismic Project Recommendations © 2018 Microsoft Corporation © 2018 DigitalGlobe ©CNES (2018) Distribution Airbus DS RIV E R C H A N N E L 1-21 TO 1-23 1-28 TO 1-32, AND 1-34 1-27 1-4 1-8 1-6 1-33 1-2 1-26 1-5 1-11 1-12 1-3 1-1 1-9 1-25 1-16 TO 1-20 1-7. 1-10,1-13 TO 15, AND 1-24 3000 SCALE IN FEET PLANT 1 STRUCTURES LEGEND 1-1 Waste Sludge Thickeners (DAFT) Pump Room 1-2 Blower Building (AS1) and PEPS 1-3 Plant Water Pump Station and Power Building 6 1-4 City Water Pump Station 1-5 Power Building 2 1-6 Power Building 4 1-7 Power Building 5 1-8 Control Center1-9 12 kV Service Center1-10 Central Power Generation Building 1-11 Aeration Basins 1-101-12 Secondary Clarifiers 1-26 1-13 Digester 5 1-14 Digesters 5-6 Pump Room 1-15 Digester 6 1-16 Digester 7 1-17 Digesters 7-8 Pump Room 1-18 Digester 8 1-19 Digesters 9-10 1-20 Digesters 9-10 Pump Room 1-21 Digesters 11-16 1-22 Digesters 11-14 Pump Room 1-23 Digesters 15-16 Pump Room 1-24 Gas Holder1-25 Effluent Junction Box1-26 Solids Storage Facility 1-27 Chiller Building 1-28 Warehouse Building 1-29 Shop Building A 1-30 Shop Building B and 3 1-31 Buildings 5 and 6 1-32 Auto Shop 1-33 PEDB21-34 Laboratory Complex PLANT 1 BOUNDARY NO DEFICIENCY IDENTIFIED DEFICIENCY AT BSE-1E ONLY DEFICIENCY AT BSE-1E AND BSE-2E LEGEND PROJECT NO: FIGURE RESULTS OF STRUCTURAL EVALUATIONS PLANT 1ORANGE COUNTY SANITATION DISTRICTFOUNTAIN VALLEY, CALIFORNIA JULY 2019 4.1HL1635 SANTA A N A R I V E R CONC R E T E L I N E D C H A N N E L TA L B E R T M A R S H A B C D 2-1 2-2 2-3 2-4 2-8 2-9 2-10 2-11 2-13 2-7 2-16 2-22 2-23 2-24 2-28 2-19 2-21 2-5 2-12 2-26 2-30 2-31 2-17 2-29 2-32 2-6 2-27 2-20 2-18 2-14 2-15 PROJECT NO: FIGURE RESULTS OF STRUCTURAL EVALUATIONSPLANT 2ORANGE COUNTY SANITATION DISTRICT HUNTINGTON BEACH, CALIFORNIA JULY 2019 4.2HL1635 PLANT 2 STRUCTURES LEGEND 2-1 DAFT A, B, & C Gallery 2-2 DAFT D Gallery & WSSPS 2-3 RAS PS East2-4 RAS PS West2-5 PEPS & MAC 2-6 Operations/Control Center Bldg 2-7 12 kV Service Center 2-8 Power Building B 2-9 Power Building C 2-10 Power Building D 2-11 City Water Pump Station 2-12 12 kV Distribution Center B 2-13 12 kV Distribution Center D2-14 Headworks Power Bldg A 2-15 Headworks Power Bldg B 2-16 Headworks Standby Power Building 2-17 Central Power Generation Building 2-18 Aeration Basins A-H 2-19 Gas Holder 2-20 Secondary Clarifiers A-L 2-21 DAFTs A-C 2-22 DAFT D 2-23 Surge Tower No. 1 2-24 Surge Tower No. 2 2-25 (Structure Omitted from Study) 2-26 Truck Loading 2-27 Maintenance Building 2-28 Boiler Building 2-29 OOBS2-30 12kV Distribution Center A (Tier 1 Only) 2-31 SEJB 2-32 JBC 3000 SCALE IN FEET PLANT 1 BOUNDARY NO DEFICIENCY IDENTIFIED DEFICIENCY AT BSE-1E ONLY DEFICIENCY AT BSE-1E AND BSE-2E NO EVALUATION OF POTENTIAL DEFICIENCIES LEGEND TITLE1TITLE2SITE LOCATION Figure 12 Project No: HM1217 DATE OC S D -8x 1 1 N P 4 -Wit h S c a l e a n d N o r t h A r r o w . d o c x PROJECT PRIORITIZATION APPROACH OCSD PS15-06 ORANGE COUNTY, CALIFORNIA Figure 7.1 Project No: HL1635 JULY 2019 HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 7/19/2019 APPENDIX A Technical Memorandum 2 (provided under separate cover) HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 7/19/2019 APPENDIX B Technical Memorandum 3 (Volumes 1 through 3 provided under separate cover) HL1635\PS15-06 Geosyntec Project Report - FINAL-Rev 2.docx 7/19/2019 APPENDIX C Meeting Minutes List of Meetings with OCSD Staff OCSD PS15-06 Orange County, California 1.5.1 Kickoff Meeting 2017-08-15 1.5.2 Plant 1 Workshop 2017-10-10 1.5.3 Plant 2 Workshop 2017-10-11 1.5.4 Pre-TM1 Workshop 2017-10-25 2.6.1 Plant 1 Pre-Investigation Workshop 2017-12-20 Meeting Minutes Not Included 2.6.2 Plant 2 Pre-Investigation Workshop 2017-12-19 Meeting Minutes Not Included 2.6.3 Project Progress Update 2018-08-15 3.9.2 Technical Exchange Meeting #3 2018-08-27 3.9.3 Technical Discussion 2018-09-06 Meeting Minutes Not Included 3.9.4 Technical Exchange Meeting #1 2018-04-26 3.9.5 Technical Exchange Meeting #2 2018-07-10 4.6.1 TM3 Review Meeting 2018-11-05 4.6.2 Task 4 Kickoff 2018-11-14 Meeting Minutes Not Included 4.6.3 TM4 Consequence Ratings 2018-12-12 Meeting Minutes Not Included 4.6.4 TM4 Project List Review Meeting 2019-01-09 4.6.5 TM4 Review Meeting 2019-05-22 Meeting Minutes Not Included NotesSubtask No. Meeting Title Meeting Date \Mtg Minutes - OCSD 8-15-17 MEETING MINUTES SUBJECT: PS15-06 Kickoff Meeting DATE: Tuesday, August 15, 2017 TIME: 10:30 a.m. PST LOCATION: OCSD Eng. & Const. Conference Room 1 MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering, Doug Lanning InfraTerra – Ahmed Nisar OCSD – Don Cutler, Mike Lahlou, Kathy Millea, Eros Yong, Martin Dix, David Halverson, Cyril Davies, Jeff Mohr, Mike Dorman 1. Safety Moment a. Presented by Chris Conkle b. Topic: Personal Earthquake Preparedness 2. Introductions a. Mr. Conkle introduced Geosyntec’s team b. Mr. Cutler introduced potential OCSD stakeholders. c. OCSD Engineering will have a leading role while O&M will have a more limited role. 3. Project Objectives a. Geosyntec outlined its project objectives culminating in a Seismic CIP & Implementation Plan PS15-06 TM4 Appendix C 2 PS15-06 Kick-off Meeting Minutes August 15, 2017 Page 2 4. Project Organization a. Geosyntec outlined its organizational structure. 5. Project Approach a. Geosyntec described its project approach. See Evaluation Flow Chart and Meetings List attached. 6. Scope of Work a. Geosyntec provided a description of the four scope of work tasks. i. Task 1 - Background Development ii. Task 2 - Geotechnical Evaluations iii. Task 3 - Structural Evaluations 1. Discussed that Tier 2/3 selections will be made based on input from OCSD, Geotech and Structural team members iv. Task 4 – Project Report 7. Baseline Schedule a. Geosyntec described the schedule which includes the following draft deliverable dates. See attached schedule handout. i. TM 1 Draft:10/31/17 ii. TM 2 Draft: 8/9/18 iii. TM 3 Draft: 8/9/18 iv. TM 4 Draft: 1/24/19 8. Data Review Process a. Discussed the Geosyntec team’s approach to geotechnical, structural, and surface fault rupture data review 9. Other Discussion Items a. Technical support for OCSD will be provided by Jacobs (Kirk, John, Elias) b. Geosyntec’s structural cut sheets will include the timeline for the next planned improvement project for each structure to aid in planning ***** Attachments • PowerPoint slides from OCSD Presentation 8-15-17 • Meeting handout: Evaluation Flow Chart • Meeting handout: PS15-06 Meetings • Meeting handout: PS15-06 Draft Schedule PS15-06 TM4 Appendix C 3 Orange County Sanitation District Orange County Sanitation District KICKOFF MEETING SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 PS 15-06 | August 15, 2017 PS15-06 TM4 Appendix C 4 Orange County Sanitation District Personal Earthquake Preparedness •Anniversary of the August 15, 2007 Pisco, Peru EQ (Mw=8.0) 2GEER, 2007PS15-06 TM4 Appendix C 5 Orange County Sanitation District Personal Earthquake Preparedness •Your Minimum Home Earthquake Kit •Food –3 days •Flashlights and Spare Batteries •Water –1 gallon per person per day (3 days) •Portable Radio and Spare Batteries •First Aid Kit (a good one) •Fire Extinguisher (ABC) •Important papers and Cash •Gas/Water Shutoff Tools •Home Preparedness •Secure contents –these are what injure people •If in doubt -Consult a structural (and geotechnical) engineer! 3 PS15-06 TM4 Appendix C 6 Orange County Sanitation District Agenda •Safety Moment •Introductions •Project Objectives •Project Approach •Project Organization •Scope of Work •Task 1 -Background Development •Task 2 -Geotechnical Evaluations •Task 3 -Structural Evaluations •Task 4 -Project Report •Baseline Schedule •Data Review Process 4 PS15-06 TM4 Appendix C 7 Orange County Sanitation District Introductions OCSD •Don Cutler –Project Manager •Mike Lahlou –Project Engineer •Jacobs (Technical Review) Geosyntec •Chris Conkle –Project Manager •Chris Hunt –Project Director/Hazards Carollo •James Doering –Vulnerability •Doug Lanning –Strategic Planning InfraTerra •Ahmed Nisar –Alternatives & Recommendations 5 PS15-06 TM4 Appendix C 8 Orange County Sanitation District Potential Stakeholders 6 Department Staff Div. Planning Kathy Millea/Eros Yong 740 Engineering Dean Fisher/Martin Dix/ Mike Dorman 760 and 770 Operations Jon Bradley/Tony Lee/ Umesh Murthy 830 and 840 Maintenance Jed Gonzales/Don Stokes 870 and 880 Risk Rich Spencer 161 PS15-06 TM4 Appendix C 9 Orange County Sanitation District Background and Justification •Many structures built prior to CBC 2001 •Many structures built prior to consensus on liquefaction (1998) •Many of these structures are at risk of damage and could take a long time to put back to service •Plant 2 is located over a major fault system (Newport- Inglewood Fault) 7 PS15-06 TM4 Appendix C 10 Orange County Sanitation District Project Objectives •Understanding of site geo-seismic hazards •Efficient structural assessments •Combined approach to the geotechnical and structural aspects to develop mitigation options/costs •Focus on OCSD selected structures to allow for ultimate prioritization •Report findings effectively to OCSD stakeholders •Seismic CIP & Implementation Plan •Project Planning Level Costs •Project Prioritization 8 PS15-06 TM4 Appendix C 11 Orange County Sanitation District Project Team Approach provides expertise in three critical areas: 9 PS15-06 TM4 Appendix C 12 Orange County Sanitation District 10 Orange County Sanitation District Risk & Reliability Technical Team Chris Hunt, Ph.D., P.E., G.E. (Geosyntec) Hazards James Doering, S.E., P.E. (Carollo) Vulnerability Ahmed Nisar, P.E. (InfraTerra) Alternatives and Recommendations Doug Lanning, P.E., PMP (Carollo) Strategic Planning OCSD Project Manager Don Cutler, P.E., BCEE OCSD Project Engineer Mike Lahlou Project Manager Chris Conkle, P.E., G.E. Project Director Chris Hunt, Ph.D., P.E., G.E. Project Organization PS15-06 TM4 Appendix C 13 Orange County Sanitation District Project Approach 11 Structural Evaluations Geotechnical Evaluations Mitigation Recommendations Task 1 Task 2 Task 2 and 3 Task 4 Project Report Background Development PS15-06 TM4 Appendix C 14 Orange County Sanitation District Meetings 12 •17 Formal Meetings Planned •Numerous Informal Meetings •Timing selected to allow efficient decision making •Proven program management approach PS15-06 TM4 Appendix C 15 Orange County Sanitation District Task 1 -Background Development 13 PS15-06 TM4 Appendix C 16 Orange County Sanitation District Task 1 -Background Development 14 PS15-06 TM4 Appendix C 17 Orange County Sanitation District Task 1 -Background Development 15 Plant # Structure Name Photograph Class Seismicity and Seismic Evaluation and Performance Objectives Mitigation Measures & Costs Process criticality, etc. Discussion of Risk Ranking and Prioritization Geohazards Idealized Soil Profile Structural Assessment & Failure Modes PS15-06 TM4 Appendix C 18 Orange County Sanitation District Task 2 –Geotechnical Evaluations 16 PS15-06 TM4 Appendix C 19 Orange County Sanitation District Task 3 –Structural Evaluations 17 Non-process Buildings Process Buildings Misc Structures Basins & Clarifiers Digesters / DAFTs . PS15-06 TM4 Appendix C 20 Orange County Sanitation District Task 3 –Structural Evaluations 18 Tier 3 -Systematic Tier 2 –Closer look Tier 1 -Screening PS15-06 TM4 Appendix C 21 Orange County Sanitation District Task 3 –Structural Evaluations 19 Tier 1 –Screening is organized by building type PS15-06 TM4 Appendix C 22 Orange County Sanitation District Task 3 –Structural Evaluations 20 Tier 2 –Deficiency-based Evaluation (Targeted) PS15-06 TM4 Appendix C 23 Orange County Sanitation District Task 3 –Structural Evaluations 21 Tier 3 –Systematic Evaluations for Special Cases PS15-06 TM4 Appendix C 24 Orange County Sanitation District Task 4 –Prioritization 22 Likelihood of Failure (LoF) Consequence of Failure (CoF) High Low High Risk Low Risk HighLow PS15-06 TM4 Appendix C 25 Orange County Sanitation District Task 4 –Consequence & Recommendations 23 PS15-06 TM4 Appendix C 26 Orange County Sanitation District Baseline Schedule 24 PS15-06 TM4 Appendix C 27 Orange County Sanitation District Data Review Process –Geotechnical 25 •Identify/catalog existing information •Develop tailored investigation (CPTs and Borings) approach in TM1 to supplement existing information where needed •Develop appropriate assumptions PS15-06 TM4 Appendix C 28 Orange County Sanitation District Data Review Process –Structural 26 •Identify/catalog existing representative information for each structure •Proceed with site visits and confirm as-built information •Develop appropriate assumptions PS15-06 TM4 Appendix C 29 Orange County Sanitation District Data Review Process –Surface Fault Rupture 27 •No new field investigation planned •Use best available existing hazard information to identify affected structures •What is the magnitude of the hazard? •Develop appropriate assumptions •Evaluate retrofit options to address the combined seismic hazards Bray and Oettle, 2012PS15-06 TM4 Appendix C 30 Orange County Sanitation District Data Gaps –Fault Rupture 28 PS15-06 TM4 Appendix C 31 Orange County Sanitation District Thank You! 29 PS15-06 TM4 Appendix C 32 TASK 4 CIP DevelopmentPrioritizationCost EstimatingVulnerability Strategic Planning Hazards/Vulnerability/Mitigation TASK 2 AND 3 All TASK 1 Prioritize Project for Seismic Improvement Develop Seismic CIP for Implementation Conduct Additional Study of Mitigation Approach as Needed Back to any step as necessary Mitigation Plan meets OCSD Objectives? Prepare Cost Estimate for Ground Improvement Structural PerformanceAcceptable? NO NODevelop Ground Improvement Approach Finalize Seismic Evaluation Approach NO YES YES SeismicHazard Geotechnical Investigation Structural Evaluation Combine Initial Mitigation Options and Cost Estimates Ground DeformationUnacceptable Structurally? Geotechnical Evaluation Retrofit/Replace Retrofit Replace Prepare Cost Estimate Prepare Cost Estimate YES TASK 2 Meeting with OCSD Combined Geotechnical & Structural Evaluation Flow Chart PS15-06 TM4 Appendix C 33 SOW ATTACHMENT 2 PROJECT NO. PS15-06 1 of 3 SCOPE OF WORK – ATTACHMENT 2 Proposed Project Meetings Task Section Meeting General Objectives Technical Objectives Principal OCSD Participants Notes on Timing Co n k l e Hu n t Do e r i n g La n n i n g Ni s a r Meeting Duration Pr e m e e t i n g ? ( Y / N ) Task 1 ‡= Attendee †= Available by Phone 1.5.1 Kick-off Meeting Introduce CONSULTANT’s project team; Discuss scope and schedule of project Discuss data gaps and CONSULTANT’s approach for either acquiring the missing data or establishing appropriate assumptions as well as anticipated time impacts to the project due to data gaps. Management Project start ‡ ‡ ‡ ‡ ‡ 2 hours N 1.5.2 Plant 1 Workshop Review the various structures, stakeholder provide their priorities (which structure can be off line after EQ, etc.) Key Plant Operations and Maintenance Staff during the course of the development of the TM1 (approximately 1- 2 months into the project.) ‡ ‡ ‡ ‡ ‡ 3 hours Y 1.5.3 Plant 2 Workshop Review the various structures, stakeholder provide their priorities (which structure can be off line after EQ, etc.) Key Plant Operations and Maintenance Staff during the course of the development of the TM1 approach and (approximately 1-2 months into the project.) ‡ ‡ ‡ ‡ ‡ 3 hours N – Combine with 1.5.2 1.5.4 Pre TM1 meeting with OCSD Staff Review proposed approach as outlined in TM1 with OCSD management Management prior to the delivery of the draft of TM1 for review ‡ ‡ ‡ ‡ ‡ 2 hours Y Task 2 2.6.1 Plant 1 Pre-Investigation Workshop Prior to conducting subsurface testing to coordinate with SANITATION DISTRICT staff on potential interruption to operations. Key Plant Operations and Maintenance Staff Prior to field investigation ‡ ‡ 2 hours Y PS15-06 TM4 Appendix C 34 SOW ATTACHMENT 2 PROJECT NO. PS15-06 2 of 3 Task Section Meeting General Objectives Technical Objectives Principal OCSD Participants Notes on Timing Co n k l e Hu n t Do e r i n g La n n i n g Ni s a r Meeting Duration Pr e m e e t i n g ? ( Y / N ) 2.6.2 Plant 2 Pre-Investigation Workshop Prior to conducting subsurface testing to coordinate with SANITATION DISTRICT staff on potential interruption to operations. Key Plant Operations and Maintenance Staff Prior to field investigation ‡ ‡ 2 hours N – Combine with 2.6.1 2.6.3 Pre-TM2 Meeting with OCSD Staff Geotechnical team and the structural team communicate general findings and alternatives for soil improvements based on the identified deficiencies Present Pre Draft TM2 Management After completion of bulk of analysis, prior to TM2 Completion ‡ ‡ ‡ † † 2 hours Y Task 3 3.9.2 Plant 1 Workshop to Review Draft Findings (includes former 2.6.4) Prior to completion of TM2/TM3 present the draft findings and incorporate comments received Present alternatives for retrofit/mitigation. Management, Plant Stakeholders Prior to completion of TM2/TM3 draft ‡ ‡ ‡ ‡ ‡ 3 hours Y 3.9.3 Plant 2 Workshop to Review Draft Findings (includes former 2.6.5) Prior to completion of TM2/TM3 present the draft findings and incorporate comments received Present alternatives for retrofit/mitigation. Management, Plant Stakeholders Prior to completion of TM2/TM3 draft ‡ ‡ ‡ ‡ ‡ 3 hours Y 3.9.4 First TM3 Findings Meeting with OCSD Staff Informal meeting during development of recommendations Cutler and Lahlou TBD, prior to 3.9.2 and 3.9.3 ‡ † ‡ † ‡ 3hours N 3.9.5 Second TM3 Findings Meeting with OCSD Staff Informal meeting during development of recommendations Cutler and Lahlou TBD, prior to 3.9.2 and 3.9.3 ‡ † ‡ † ‡ 3 hours N Task 4 4.6.1 Plant 1 Pre-Report Workshop Obtain OCSD review and input when we have our findings Final input on retrofit options Plant Stakeholders 1 month prior to TM4 draft ‡ † ‡ ‡ ‡ 3 hours Y PS15-06 TM4 Appendix C 35 SOW ATTACHMENT 2 PROJECT NO. PS15-06 3 of 3 Task Section Meeting General Objectives Technical Objectives Principal OCSD Participants Notes on Timing Co n k l e Hu n t Do e r i n g La n n i n g Ni s a r Meeting Duration Pr e m e e t i n g ? ( Y / N ) 4.6.2 Plant 2 Pre-Report Workshop Obtain OCSD review and input when we have our findings Final input on retrofit options Plant Stakeholders 1 month prior to TM4 draft ‡ † ‡ ‡ ‡ 3 hours Y 4.6.3 Plant 1 Workshop to Present Draft Findings Present the findings in the draft technical memorandum to SANITATION DISTRICT staff and receive comments Management. Plant Stakeholders Upon completion of TM4 draft ‡ † ‡ ‡ † 2 hours Y 4.6.4 Plant 2 Workshop to Present Draft Findings Present the findings in the draft technical memorandum to SANITATION DISTRICT staff and receive comments Management. Plant Stakeholders Upon completion of TM4 draft ‡ † ‡ ‡ † 2 hours Y 4.6.5 Follow-up Meeting to Discuss OCSD Comments Discuss SANITATION DISTRICT’s comments on the draft Project Report Management Upon receipt of TM4 comments ‡ ‡ 2 hours y 4.6.6 Presentation of Final Report Informational presentation to SANITATION DISTRICT staff All relevant district staff Upon report finalization ‡ ‡ ‡ ‡ ‡ 3 hours Y PS15-06 TM4 Appendix C 36 ID Task Name Duration Start Finish 1 Notice to Proceed 0 days 7/26/17 7/26/17 2 Task 1 ‐ Background Development 95 days 7/26/17 12/7/17 3 1.1 ‐ Review Documents 35 days 7/26/17 9/12/17 18 1.2 ‐ Identify Data Gaps 15 days 8/23/17 9/12/17 22 1.3 ‐ Develop Evaluation Approach 60 days 7/26/17 10/17/17 33 1.4 ‐ Technical Memorandum 1 45 days 10/4/17 12/7/17 45 1.5 ‐ Meetings/Workshops 54 days 8/15/17 10/27/17 50 Task 2 ‐ Geotechnical Investigation, Evaluation, Options, and Recommendations 229 days 10/18/17 9/13/18 51 2.1 ‐ Geotechnical Investigation 37 days 12/1/17 1/30/18 58 2.2 ‐ Geotechnical Engineering Analysis 94 days 10/18/17 3/8/18 72 2.3 ‐ Strategies to Mitigate Deficiencies and Geotechnical Recommendations 15 days 2/23/18 3/15/18 76 2.4 ‐ AACEI Cost Estimate 10 days 3/9/18 3/22/18 79 2.5 ‐ Technical Memorandum 2 75 days 6/1/18 9/13/18 91 2.6 ‐ Meetings and Workshops 129 days 12/11/17 6/15/18 95 Task 3 ‐ Seismic Evaluation, Options, and Recommendations 194 days 12/15/17 9/20/18 96 3.1 ‐ Site Visits 20 days 12/15/17 1/19/18 103 3.2 ‐ Identify Non‐Destructive Testing 4 wks 1/22/18 2/16/18 Notice to Proceed Task 1 ‐ Background Development 1.1 Review Documents 1.2 ‐ Identify Data Gaps 1.3 ‐ Develop Evaluation Approach 1.4 ‐ Technical Memorandum 1 1.5 ‐ Meetings/Workshops Task 2 ‐ Geotechnical Investigation, Evaluation, Options, and Recommendations 2.1 ‐ Geotechnical Investigation 2.2 ‐ Geotechnical Engineering Analysis 2.3 ‐ Strategies to Mitigate Deficiencies and Geotechnical Recommendations 2.4 ‐ AACEI Cost Estimate 2.5 ‐ Technical Memorandum 2 2.6 ‐ Meetings and Workshops Task 3 ‐ Seismic Evaluation, Options, and Recommendations 3.1 ‐ Site Visits 3.2 ‐ Identify Non‐Destructive Testing Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Task Summary Manual Milestone OCSD PS15‐06 SCHEDULE Page 1 of 2 Date: 8/14/17 PS15-06 TM4 Appendix C 37 ID Task Name Duration Start Finish 104 3.3 ‐ Tier 1 Evaluations 40 days 2/16/18 4/12/18 111 3.4 ‐ Tier 2/Tier 3 Evaluations 65 days 3/2/18 5/31/18 118 3.5 ‐ Evaluate Structures that do not Comply with ASCE 41‐13 11 wks 3/16/18 5/31/18 119 3.6 ‐ Recommend Strengthening/Retrofit Improvements 50 days 4/13/18 6/21/18 123 3.7 ‐ AACEI Class V Cost Estimates 8 wks 5/25/18 7/19/18 124 3.8 ‐ Technical Memorandum 3 65 days 6/22/18 9/20/18 136 3.9 ‐ Meetings/Workshops 27 days 6/22/18 7/30/18 141 Task 4 ‐ Project Report 112 days 9/21/18 3/8/19 142 4.1 ‐ Compile Task 1 through Task 3 Work 16 days 9/21/18 10/12/18 143 4.2 ‐ Geotechnical & Structural Mitigation Recommendations 30 days 10/15/18 11/27/18 147 4.3 ‐ Criticality Determination and Ranking 5 wks 11/28/18 1/10/19 148 4.4 ‐ Risk Ranking 5 wks 11/28/18 1/10/19 149 4.5 Project Report 55 days 12/5/18 2/28/19 161 4.6 ‐ Meetings/Workshops 51 days 12/19/18 3/8/19 168 Task 5 ‐ Project Management 406 days?7/26/17 3/8/19 3.3 ‐ Tier 1 Evaluations 3.4 ‐ Tier 2/Tier 3 Evaluations 3.5 ‐ Evaluate Structures that do not Comply with ASCE 41‐13 3.6 ‐ Recommend Strengthening/Retrofit Improvements 3.7 ‐ AACEI Class V Cost Estimates 3.8 ‐ Technical Memorandum 3 3.9 ‐ Meetings/Workshops Task 4 ‐ Project Report 4.1 ‐ Compile Task 1 through Task 3 Work 4.2 ‐ Geotechnical & Structural Mitigation Recommendations 4.3 ‐ Criticality Determination and Ranking 4.4 ‐ Risk Ranking 4.5 Project Report 4.6 ‐ Meetings/Workshops Task 5 ‐ Project Management Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Task Summary Manual Milestone OCSD PS15‐06 SCHEDULE Page 2 of 2 Date: 8/14/17 PS15-06 TM4 Appendix C 38 \Mtg Minutes - OCSD 10-10-17 MEETING MINUTES SUBJECT: PS15-06 Plant 1 Workshop DATE: Tuesday, October 10, 2017 TIME: 2:30 p.m. PST LOCATION: OCSD Plant 1, Conference Room C MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering, Doug Lanning InfraTerra – Ahmed Nisar, Nikolay Doumbalski OCSD – Don Cutler, Mike Lahlou, Kathy Millea, Jim Spears, Jeff Mohr, Eros Yong, Nasrin Nasrollahi, Jon Bradley 1. Safety Moment a. Presented by Chris Conkle b. Topic: NFPA Fire Prevention Week 2. Meeting Objectives 3. Introductions a. Mr. Conkle introduced Geosyntec’s team 4. Review Project Background/Objectives a. OCSD input regarding overall project vision: i. Project is focused on the structures, as there are already programs in place that look at other elements from a non-seismic standpoint ii. The FMP lists structures that are in the pipeline over the next 20 years PS15-06 TM4 Appendix C 39 PS15-06 Plant 1 Workshop Minutes October 10, 2017 Page 2 iii. This project is set up to result in rankings so that OCSD can incorporate seismic projects into the FMP priority list b. Per Mr. Cutler, within the confines of 15-06, OCSD will get a good idea of the vulnerabilities at the plants. This will inform some of the planning associated with non-15-06 projects. 5. Review Project Approach a. Structural/Geotechnical Interaction is a key project element. 6. Geotechnical Hazard Primer 7. Task 1 – Background Development Update a. Geotechnical Conditions at Plant 1 b. Structural Information at Plant 1 i. A lot of the missing information may be foundation related. Drawings show different pile types, but not which one was actually built. 8. Stakeholder Input – Plant 1 a. Equipment failures are a significant performance concern. Though not an integral part of current scope, some qualitive comments with regard to performance of these elements may be made. b. Maintenance may have opinions on criticality of structures and their buildings. 9. Q&A Q: Are we looking at critical junctions across the site and other elements aside from the structures? A: Some elements are to be looked at under separate projects, and it not the intent of PS15-06 to duplicate that effort. Q: Should we identify critical junctions that need to be added to the program? For example, PEDB2 junction box: 30’x40’, 25’ below grade and 10’ above. Pile supported. A: Geosyntec will discuss with Cutler an approach to evaluating additional example junction structures as part of this project. 10. Additional Discussion Items a. Connections between elements will be key to seismic performance. This isn’t incorporated into the current scope. While detailed evaluation will not be performed some qualitive comments will be provided in PS15-06 were relevant to study structures. PS15-06 TM4 Appendix C 40 PS15-06 Plant 1 Workshop Minutes October 10, 2017 Page 3 b. Truck Loading Facility (1-32) - should be Class I - need to get solids out of the plant. c. Should warehouse be critical structure because all parts are stored in there? Want a yellow/green tag after the earthquake. Potentially consider warehouse a Class I. d. The results of this study may not change the order of projects, but more likely may change the type of project. * * * * * Attachments • PowerPoint slides from OCSD Presentation 10-10-17 • Meeting handout: OCSD PS15-06 Task 1 to 4 Approach Flowchart • Meeting handout: Structures Data Gap Summary • Meeting handout: Plant 1 Structures for Seismic Evaluation Map • Meeting handout: Plant 1 Hydraulic Flow Diagram PS15-06 TM4 Appendix C 41 Orange County Sanitation District Orange County Sanitation District PLANT 1 WORKSHOP SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 PS 15-06 | OCTOBER 10, 2017 PS15-06 TM4 Appendix C 42 Orange County Sanitation District Agenda •Safety Moment •Meeting Objectives •Introductions •Review Project Background/Objectives •Review Project Approach •Geotechnical Hazard Primer •Task 1 –Background Development Update •Geotechnical Conditions at Plant 1 •Structural Information at Plant 1 •Stakeholder Input –Plant 1 2 PS15-06 TM4 Appendix C 43 Orange County Sanitation District Safety Moment: NFPA Fire Prevention Week •Santa Rosa –Tubbs Fire 3Photos: Kent Porter, Santa Rosa Press DemocratPS15-06 TM4 Appendix C 44 Orange County Sanitation District Safety Moment: Fire Safety Week •Harden your home 4 PS15-06 TM4 Appendix C 45 Orange County Sanitation District Meeting Objectives •Gather information regarding particular concerns at Plant 1 •Illustrate the project approach at Plant 1 •There are hazards –need smart solutions •TM1 approach that meets OCSD needs 5 PS15-06 TM4 Appendix C 46 Orange County Sanitation District Introductions OCSD •Don Cutler –Project Manager •Mike Lahlou –Project Engineer •Jacobs (Technical Review) Geosyntec •Chris Conkle –Project Manager •Chris Hunt –Project Director/Hazards Carollo •James Doering –Vulnerability •Doug Lanning –Strategic Planning InfraTerra •Ahmed Nisar –Alternatives & Recommendations 6 PS15-06 TM4 Appendix C 47 Orange County Sanitation District Plant 1 Stakeholders 7 Department Staff Div. Planning Kathy Millea/Eros Yong 740 Engineering Dean Fisher/Martin Dix/ Mike Dorman 760 and 770 Operations Jon Bradley/Tony Lee/ Umesh Murthy 830 and 840 Maintenance Jed Gonzales/Don Stokes 870 and 880 Risk Rich Spencer 161 PS15-06 TM4 Appendix C 48 Orange County Sanitation District Project Background •Recognized potential for structural and geo-seismic vulnerabilities •An overall system wide approach is needed for identifying and addressing deficiencies 8 PS15-06 TM4 Appendix C 49 Orange County Sanitation District Seismic Sources 9 20 % 5%4% 1% 3% Mean 30-Year (2014 –2044) Probabilities of M >= 6.7 UCERF3 (USGS, SCEC) PS15-06 TM4 Appendix C 50 Orange County Sanitation District Sloshing damage to sludge scraper chain rail at Tillman water reclamation plant, Van Nuys –1994 Northridge Earthquake Broken Tie-Down Straps – LarwinTank; 1994 Northridge Earthquake Gas holding tanks in Oshamanbe area on soft soils were not damaged but the underground piping was damaged by ground settlement –1995 Hokkaido Earthquake Damaged water stop in aeration basin –1995 Kobe Earthquake Damage to scraper chain in sedimentation tanks –1995 Kobe Earthquake Wood baffles afloat after being dislodged by sloshing at a water treatment plant – 1964 NigataEarthquake Waste Water Systems Past Earthquake Performance PS15-06 TM4 Appendix C 51 Orange County Sanitation District Gas holder (2,300 cu. m.) inclined about 4-inches as “Nuttari” area –1964 Nigata Earthquake Sedimentation basin of the “Tamongawa” pumping station was broken at the center –1964 Nigata Earthquake Wood baffles damaged by sloshing at a water treatment plant –1964 NigataEarthquake Damage to overhead bridge – 1964 Nigata Earthquake Waste Water Systems Past Earthquake Performance PS15-06 TM4 Appendix C 52 Orange County Sanitation District Project Objectives •Overall PS15-06 •Develop system for addressing these vulnerabilities going forward •Apply this procedure to select structures first •Understanding of site geo-seismic hazards –Task 2 •Efficient structural assessments –Task 3 •Combined approach to the geotechnical and structural aspects to develop mitigation options/costs –Task 2/3 •Seismic CIP & Implementation Plan •Project Planning Level Costs •Project Prioritization 12 PS15-06 TM4 Appendix C 53 Orange County Sanitation District What is the Overall Vision? 13 PS15-06 TM4 Appendix C 54 Orange County Sanitation District 14 PS15-06 Project Report Evaluation of Other System Components (Piping, Electrical, etc.) PS15-06 Seismic CIP / Implementation (Vulnerable Structures) Understanding of Broader Site Issues (Geotechnical/ Structural) Future CIPs on Non PS15-06 Facilities Produces PS15-06 Prior Studies Prior Projects Produces Geotechnical/ Structural Evaluations of Non PS15-06 Structures Outside PS15-06 Informs PS15-06 Outcomes PS15-06 TM4 Appendix C 55 Orange County Sanitation District 15 Project Approach PS15-06 TM4 Appendix C 56 Orange County Sanitation District •Ground Shaking •Other Effects •Liquefaction •Lateral Spreading •Surface Fault Rupture (Plant 2) Seismic Hazards to be Evaluated? 16 Gas holder (2,300 cu. m.) inclined about 4- inches in “Nuttari” area –1964 Nigata Earthquake PS15-06 TM4 Appendix C 57 Orange County Sanitation District •Cause of other hazards •Need to understand characteristic of ground motions •Effects of site conditions on shaking •Consider the effects of numerous sources/events •Amplitude of Shaking •Peak Ground Acceleration (PGA) •Most Common Measure •Frequency •Structures are very sensitive to frequency of loading •Soil Deposits act as filters Ground Shaking 17 PS15-06 TM4 Appendix C 58 Orange County Sanitation District Ground Shaking 18 Source: GARINI, E and GAZETAS, G “M 7.1 Puebla (Mexico) 19‐9‐17 Earthquake: A near “repeat” of the M 8.1 Earthquake of 1985 that had devastated Mexico City (19 000 deaths)” Preliminary Report Dated: 25 September 2017 PS15-06 TM4 Appendix C 59 Orange County Sanitation District Ground Shaking 19 Source: GARINI, E and GAZETAS, G “M 7.1 Puebla (Mexico) 19‐9‐17 Earthquake: A near “repeat” of the M 8.1 Earthquake of 1985 that had devastated Mexico City (19 000 deaths)” Preliminary Report Dated: 25 September 2017 T=1.4 sec –Natural Period of 5-10 sty structure PS15-06 TM4 Appendix C 60 Orange County Sanitation District Ground Shaking 20 PS15-06 TM4 Appendix C 61 Orange County Sanitation District •Generation of excess pore pressures under cyclic loading •Contractive Response •Rapid Loading -“Undrained” •Leads to softening of soils Liquefaction 21 LiquefactionWater’s ResponseEarthquakeLoose Soil PS15-06 TM4 Appendix C 62 Orange County Sanitation District Liquefaction 22 PS15-06 TM4 Appendix C 63 Orange County Sanitation District •Liquefaction Effects •Level Ground Liquefaction -settlement of buildings, retaining wall failure •Lateral Spreading Liquefaction 23 PS15-06 TM4 Appendix C 64 Orange County Sanitation District Liquefaction Effects 24 Level Ground Liquefaction –Ground Oscillation •Effects: settlement of buildings, retaining wall failure PS15-06 TM4 Appendix C 65 Orange County Sanitation District Lateral Spreading 25 PS15-06 TM4 Appendix C 66 Orange County Sanitation District Lateral Spreading –Plant 1 26 PS15-06 TM4 Appendix C 67 Orange County Sanitation District •Is soil susceptible to liquefaction? •Can liquefaction be triggered? •If triggered, will damage occur? •What remediation is required? Liquefaction Evaluations 27 PS15-06 TM4 Appendix C 68 Orange County Sanitation District Task 1 –Background Review –Plant 1 28 PS15-06 TM4 Appendix C 69 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 1 29Preliminary –Based on Limited InformationPS15-06 TM4 Appendix C 70 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 1 30 Preliminary –Based on Limited Information PS15-06 TM4 Appendix C 71 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 1 31 Preliminary –Based on Limited Information PS15-06 TM4 Appendix C 72 Orange County Sanitation District Task 1 –Example Structural Summary 32 PS15-06 TM4 Appendix C 73 Orange County Sanitation District Task 1 –Example Structural Summary 33 PS15-06 TM4 Appendix C 74 Orange County Sanitation District Task 1 –Structural Evaluations 34 •Review Available Structural Information •Drawings •Specifications •Corrosion Assessment Reports •Seismic Evaluation Reports •Site Visit •Identify Data Gaps PS15-06 TM4 Appendix C 75 Orange County Sanitation District Task 1 –Background Review – Structural Information 35 Non-process Buildings Process Buildings Misc Structures Basins & Clarifiers Digesters / DAFTs . PS15-06 TM4 Appendix C 76 Orange County Sanitation District Task 1 –Site Visit–Plant 1 36 PS15-06 TM4 Appendix C 77 Orange County Sanitation District Task 1 –Site Visit–Plant 1 37 PS15-06 TM4 Appendix C 78 Orange County Sanitation District Task 1 –Structural Evaluations 38 •Review Available Structural Information Review Project Drawings for Original Construction Request/Search for Additional Information Any missing information ? Identify Data Gaps PS15-06 TM4 Appendix C 79 Orange County Sanitation District Ground Deformation –Digesters 39 Preliminary –Based on Limited Information PS15-06 TM4 Appendix C 80 Orange County Sanitation District •All digesters are supported on piles •Good rebar detailing for most digesters •Dome to wall connection •Wall to base slab connection •Potentially vulnerable pile hoop reinforcement •Potentially vulnerable piping connections Digester Details PS15-06 TM4 Appendix C 81 Orange County Sanitation District Digester Rebar Details PS15-06 TM4 Appendix C 82 Orange County Sanitation District Pile Damage Large ground subsidence near the waterfront at the Maya Wharf District – 1995 Kobe Earthquake Large gap due to Liquefaction-induced settlement of building in Port Island –1995 Kobe Earthquake PS15-06 TM4 Appendix C 83 Orange County Sanitation District Pile Damage –Lateral Spreading Damage to piles due to lateral spreading – 1995 Kobe Earthquake PS15-06 TM4 Appendix C 84 Orange County Sanitation District Typical Pile Details PS15-06 TM4 Appendix C 85 Orange County Sanitation District Vulnerable Piping Details PS15-06 TM4 Appendix C 86 Orange County Sanitation District Review Structure List Plant 1 –OCSD Input 46 PS15-06 TM4 Appendix C 87 Orange County Sanitation District Review Structure List Plant 1 –OCSD Input 47 PS15-06 TM4 Appendix C 88 Orange County Sanitation District Review Structure List Plant 1 –OCSD Input 48 ID Number Structure Name Plant Facility Class Type Original Project Additional Projects Condition Assessment Basis Structural Data Gaps Level 1 Level 2 1-1 Waste Sludge Thickeners (DAFT) Pump Room 1 I Building P1-16 P1-36-2 Site Visit Pile info 1-2 Blower Building (AS1) and PEPS 1 I Building P1-16 P1-36-1 / P1-36-2 / P1-44-4 Site Visit Pile info Condition assessment of PEPS 1-3 Plant Water Pump Station and Power Building 6 1 I Building P1-34-2 Site Visit Pile info 1-4 City Water Pump Station 1 I Building P1-34-1 Site Visit 1-5 Power Building 2 1 I Building P1-9 P1-16 / P1-22 / P1-44-1 Site Visit 1-6 Power Building 4 1 I Building P1-22 Site Visit 1-7 Power Building 5 1 I Building P1-34-1 Site Visit 1-8 Control Center 1 I Building J-23-1 Site Visit 1-9 12 kV Service Center 1 I Building P1-34-2 Site Visit 1-10 Central Power Generation Building 1 I Building J-19-1 Site Visit Pile info 1-11 Aeration Basins 1-10 1 I Tank P1-16 P1-36-2 Condition Assessment Report for No. 1 Pile info, timber info for baffles 1-12 Secondary Clarifiers 1-26 1 I Tank P1-16 P1-36-2 / P1-82 Condition Assessment Reports for Nos. 8, 21, 22, 23 Pile info 1-13 Digester 5 1 I Tank P1-2 Pile info Condition Assessment 1-14 Digester 5 Pump Room 1 I Tank P1-2 P1-5 Site Visit 1-15 Digester 6 1 I Tank P1-5 Pile info / steel dome info Condition assessment 1-16 Digester 7 1 I Tank P1-9 P1-35-1 Pile info Condition assessment 1-17 Digester 7 Pump Room 1 I Tank P1-9 P1-14 Site Visit 1-18 Digester 8 1 I Tank P1-14 P1-35-1 Pile info Condition assessment 1-19 Digester 9-10 1 I Tank P1-16 P1-35-2 Pile info Condition assessment 1-20 Digester 9-10 Pump Room 1 I Tank P1-16 Site Visit 1-21 Digesters 11-16 1 I Tank P1-34-3 Condition Assessment Report for Digester No. 13 Pile info 1-22 Digesters 11-16 Pump Room 1 1 I Tank P1-34-3 Site Visit Pile info 1-23 Digesters 11-16 Pump Room 2 1 I Tank P1-34-3 Site Visit Pile info 1-24 Gas Holder 1 I Steel Tank P1-34-1 Condition Assessment Report 1-25 Effluent Junction Box 1 I Tank P1-33 Pile info Condition assessment 1-26 Chiller Building 1 II Building J7-4 P1-44-3 Site Visit 1-27 Warehouse Building 1 II Building J-13 J-13-2R / P1-44-3 Site Visit 1-28 Shop Building A 1 II Building J-13 P1-44-3 Site Visit 1-29 Shop Building B and Building 3 1 II Building J-13 J-20 / J-89 / P1-44-3 Site Visit 1-30 Buildings 5 and 6 1 II Building J-20 P1-44-3 Site Visit 1-31 Auto Shop 1 II Building J-12 P1-44-3 Site Visit 1-32 Solids Storage Facility 1 II Tank P1-34-2 Pile info Lean-to addition on the south side / Condition assessmentPS15-06 TM4 Appendix C 89 Orange County Sanitation District Action Items/Summary 49 •Incorporate OCSD input into Approach •Next Workshop TM1 –10/25/17 •TM1 Draft –10/31/17 PS15-06 TM4 Appendix C 90 Orange County Sanitation District Thank You! 50 PS15-06 TM4 Appendix C 91 OCSD Seismic Evaluation Document Review Request Documents Data Gaps? Plan Investigation / Site Visits Structure Classification / Reclassification Tech Memo 1 Field Gaps Doc Gaps OK Task 1 Geotechnical Investigation Structural Site Visits Key Structure? Site Response Analysis Response Spectra Seismic Inputs Evaluate Ground Deformations Geotechnical Analyses Site Model Settlement Foundation Type/Capacity Lateral Spread Fault Rupture Information Flow Direction Structural Input to Geotech Task 2 Task 3 Def. OK? Cost Estimates Ground Improvement Measures Tech Memo 2 No No Yes Data Gaps? As-Built Survey & Non-Destructive Testing Yes Structural Evaluation No Building Structures Liquid Containing Structures Geotech Input to Structural ACI 350.3 Analysis ASCE 41-13 Tier 1 Ground Def. OK? Ground Def. OK? Yes Perform. OK? Perform. OK? Structure Deformation Outputs Yes No ASCE 41-13 Tier 2 Perform. OK? FE Analysis Warranted? No No Finite Element / Tier 3 Analysis No No Strengthening / Retrofit Improvements Yes Yes Perform. OK? No Cost Estimates Tech Memo 3 Yes Yes Compile TM 1-3 Information Task 4 Incorporate Mitigation Measures Evaluate Criticality & Consequence Develop Risk Ranking Criticality, Consequences & Ranking Appropriate? Tech Memo 4 Yes No Background Development Geotechnical Evaluation Structural Evaluation Criticality & Ranking OCSD PS15-06 Task 1 to 4 Approach Flowchart 8 October 2017 Yes PS15-06 TM4 Appendix C 92 Level 1 Level 2 1-1 Waste Sludge Thickeners (DAFT) Pump Room 1 I Building P1-16 P1-36-2 Site Visit Pile info 1-2 Blower Building (AS1) and PEPS 1 I Building P1-16 P1-36-1 / P1-36-2 / P1-44-4 Site Visit Pile info Condition assessment of PEPS 1-3 Plant Water Pump Station and Power Building 6 1 I Building P1-34-2 Site Visit Pile info 1-4 City Water Pump Station 1 I Building P1-34-1 Site Visit 1-5 Power Building 2 1 I Building P1-9 P1-16 / P1-22 / P1-44-1 Site Visit 1-6 Power Building 4 1 I Building P1-22 Site Visit 1-7 Power Building 5 1 I Building P1-34-1 Site Visit 1-8 Control Center 1 I Building J-23-1 Site Visit 1-9 12 kV Service Center 1 I Building P1-34-2 Site Visit1-10 Central Power Generation Building 1 I Building J-19-1 Site Visit Pile info 1-11 Aeration Basins 1-10 1 I Tank P1-16 P1-36-2 Condition Assessment Report for No. 1 Pile info, timber info for baffles 1-12 Secondary Clarifiers 1-26 1 I Tank P1-16 P1-36-2 / P1-82 Condition Assessment Reports for Nos. 8, 21, 22, 23 Pile info 1-13 Digester 5 1 I Tank P1-2 Pile info Condition Assessment 1-14 Digester 5 Pump Room 1 I Tank P1-2 P1-5 Site Visit 1-15 Digester 6 1 I Tank P1-5 Pile info / steel dome info Condition assessment 1-16 Digester 7 1 I Tank P1-9 P1-35-1 Pile info Condition assessment 1-17 Digester 7 Pump Room 1 I Tank P1-9 P1-14 Site Visit 1-18 Digester 8 1 I Tank P1-14 P1-35-1 Pile info Condition assessment 1-19 Digester 9-10 1 I Tank P1-16 P1-35-2 Pile info Condition assessment 1-20 Digester 9-10 Pump Room 1 I Tank P1-16 Site Visit 1-21 Digesters 11-16 1 I Tank P1-34-3 Condition Assessment Report for Digester No. 13 Pile info1-22 Digesters 11-16 Pump Room 1 1 I Tank P1-34-3 Site Visit Pile info1-23 Digesters 11-16 Pump Room 2 1 I Tank P1-34-3 Site Visit Pile info 1-24 Gas Holder 1 I Steel Tank P1-34-1 Condition Assessment Report 1-25 Effluent Junction Box 1 I Tank P1-33 Pile info Condition assessment 1-26 Chiller Building 1 II Building J7-4 P1-44-3 Site Visit 1-27 Warehouse Building 1 II Building J-13 J-13-2R / P1-44-3 Site Visit 1-28 Shop Building A 1 II Building J-13 P1-44-3 Site Visit 1-29 Shop Building B and Building 3 1 II Building J-13 J-20 / J-89 / P1-44-3 Site Visit 1-30 Buildings 5 and 6 1 II Building J-20 P1-44-3 Site Visit 1-31 Auto Shop 1 II Building J-12 P1-44-3 Site Visit 1-32 Solids Storage Facility 1 II Tank P1-34-2 Pile info Lean-to addition on the south side / Condition assessment Notes OCSD - PS15-06 - Structure Data Gap Summary Structural Data Gaps ID Number Structure Name Plant Facility Class Type Original Project Additional Projects Condition Assessment Basis PS15-06 TM4 Appendix C 93 S A N T A A N A R I V E R OCWD BUILDING ABUILDINGB FLARES RAG ROOM AUTO SHOP SCRUBBERS LABORATORY PROCESSCONTROLS/INFORMATION TECHNOLOGY GAS HOLDER DIGESTER 6 DIGESTER 5 DIGESTER 7 DIGESTER 8 DIGESTER 9 DIGESTER 10 DIGESTER 11 DIGESTER 13 DIGESTER 12 DIGESTER 14 DIGESTER 15 DIGESTER 16 GUARD SHACK CONTRACTS ADMINISTRATION GRIT CHAMBERHEADWORKS 2 GRIT CHAMBERHEADWORKS 1 DUMPING PORTS WEST SCRUBBERS BUILDING NO.8 BUILDING NO.6 BUILDING NO.4 BUILDING NO.5 BUILDING NO. 2 BUILDING NO. 1 BUILDINGNO. 3 BUILDING NO.7 SAFETY TRAILER NORTH ENTRANCE AERATION BASINS1-10 BLOWER BUILDING HUMAN RESOURCES BOILER BUILDING HEADWORKS NO. 2 HEADWORKSNO. 1 POWER BUILDING 6 POWER BUILDING 4 POWER BUILDING 5 POWER BUILDING 2 CHLORINE STATION CHILLER BUILDING POWER BUILDING 3ACHLORINE BUILDING POLYMER FACILITY 2 PRIMARY CLARIFIER 4 PRIMARY CLARIFIER 5 PRIMARY CLARIFIER 3 SECONDARY CLARIFIERS 1-24 12 KV SERVICE CENTER POLYMER STORAGE AREA *SEJB OCWD GAP PUMP STATION EFFLUENT JUNCTION BOX DEWATERING BUILDING CDEWATERING BUILDING M ENGINEERING TRAILER A ENGINEERING TRAILER B TRICKLING FILTER NO. 1TRICKLING FILTER NO. 2 SUNFLOWER PUMP STATION CAKE TRANSFER STATION M CAKE TRANSFER STATION C GAS COMPRESSOR BUILDING SOLIDS STORAGE FACILITY ADMINISTRATION BUILDING CITY WATER PUMP STATION PLANT WATER PUMP STATION PRIMARY POLYMER FACILITY PURCHASING AND WAREHOUSE DIGESTER 5 & 6 PUMP ROOM 12 KV DISTRIBUTION CENTER CONTROL CENTER (OLD) OPERATIONS CONTROL CENTER PRIMARY CLARIFIERS 1 AND 2/SLUDGEPUMP ROOM/ELECTRICALBUILDING WASTEHAULER PUMPING STATION WASTEHAULER DUMPING STATION WASTE SIDESTREAM PUMP STATION PEJB-1 PRIMARY CLARIFIERS 6 THROUGH 15 METERING AND DIVERSION STRUCTURE *SEJB-3 CENTRAL POWER GENERATION BUILDING BUILDING H *PEPS FOUL AIR/ CHEMICAL HANDLING FACILITY SECONDARY CLARIFIER NO. 2 SECONDARY CLARIFIER NO. 1 J-90 (05)FE07-12 (08)P1-97 (11) J-20 (90)P1-44-3 (96) J-20 (90)P1-44-3 (96)P1-48 (00)SP2000-22 (01) J-75 (03)FE04-03 P1-27 (89)J-108 (12) P1-36-2 (00) P1-27 (89)P1-38-1 (93)J-108 (12) P1-9 (64)P1-76 (09)J-36 (11) J-20 (90)P1-44-3 (96)P1-43 (00)SP2000-22 (01) J-20 (90)P1-44-3 (96)P1-43 (00)SP1995-63 (00) J--13 (74)J-20 (90) J-20 (90)P1-44-3 (96)P1-43 (00) I-6-1 (66)P1-33 (92)P1-16 (92)J-87 (03)J-67 (07)I-9 (93) P1-34-2 (91)P1-40-2 (00) P1-34-1 (92)P1-38-1 (97) P1-16 (78)P1-22 (88)J-19-1 (94)P1-44-1 (96)J-16 (89) P1-34-2 (91)J-19-1 (94)J-17-2 (96)SP1995-76 (97)P1-38-2 (97)P1-43 (00)P1-36-2 (00)SP-94 (07) P1-34-2 (91)P1-33 (92)J-19-1 (94)P1-43 (00)J-57 (00)P1-97 (11) P1-33 (93)SP1996-59 (96)P1-42 (96)P1-48 (00)P1-38-5 (00)P1-37 (10)J-36 (11) P1-22-1 (87)P1-22 (88)P1-23R (89)P1-38-1 (93)P1-34-1 (93)J-19-1 (94)J-17-2 (96)P1-43 (00)FE02-15 (02)FE05-31 (05)J-33-1A (09)P1-37 (10) P1-33 (92)P1-38-4 (97)P1-40-2 (00)P1-48 (00)SP1999-75 (01)P1-37 (10) P1-16 (78)P1-36-2 (00)FE03-31 (03)J-87 (04)J-16 (89)P1-82 (11) J-11 (71)PW-073 (81)PW-111 (83)J-11R (85)P1-22-1 (87)J-11-2 (97)SP1998-15 (98)J-57 (00)J-11-1 (00)FE05-17 (06)FE05-42 (06) P1-16 (78)PW-072 (79)P1-18 (82)J-16 (89)P1-36-2 (00)J-87 (04)J-67 (07)FE02-23 (02)P1-82 (11) P1-1 (57)P1-1R-1 (72)PW-134 (86)P1-24R (86)P1-25 (90)P1-41-1 (94)P1-38-2 (97)P2-48 (00)P1-37 (10) J-90 (05)FE07-12 (08) J-20 (90)P1-44-3 (96) J-42 (04) J-20 (90)SP2000-22 (01) P1-28 (87)P1-3-1 (72) P1-20 (87)FE07-29 (08) P1-34-2 (91) P1-38-2 (97)P1-22 (88) P1-27-2 (00) J-21 (93)P1-48 (00) P1-9 (64)P1-76 (09) P1-9 (64)P1-76 (09)J-36 (11) P1-20 (90)J-35-2 (96) P1-13 (65)P1-3-1 (72) P1-5 (62)P1-3-2 (82)PW-085 (83) P1-76 (09) P1-34-1 (92)J-35 (00) P1-21 (88)J-71-7 (03) P1-34-3 (89)P1-38-2 (93)P1-48 (00)P1-100 (14) P1-34-3 (89)P1-38-2 (97)P1-48 (00)P1-100 (14) P1-4 (61)P1-34-1 (92)P1-48 (00)FE04-05FE05-17 P1-20 (90)P1-38-2 (93)J-35-2 (96)P1-43 (00)P1-62 (00)I-10B (11) P1-16 (78)PW-066-2 (90)P1-34-2 (91)P1-7-2 (94) P1-48-1 (96)E-265A (96)M-044 (97) J-13 (74)PW-144 (87)J-17-2 (96)J-16 (96)P1-44-3 (96) P1-20 (90)J-79-1 (12) P1-34-3 (93)P1-38-2 (97)P1-48 (00)P1-100 (14) P1-34-3 (93)P1-38-2 (97)P1-48 (00)J-57 (00)P1-100 (14) P1-16 (78)J-16 (89)P1-35-2 (93)J-35 (00)P1-100 (14) J-7-4 (92)P1-44-3 (96)P1-38-4 (97)SP2000-22 (01) P1-36-1 (93)P1-36-2 (95)J-87 (04) P1-34-3 (93)P1-38-2 (93)P1-48 (00)P1-100 (14) P1-34-3 (89)P1-38-2 (93)P1-48 (00)P1-100 (14) J-13 (74)PW-089 (81)J-16 (89)P1-44-3 (96)SP1999-47 (99)SP2000-22 (01)SP2001-02 (01)J-89 (03) P1-9 (64)J-16 (89)P1-35-1 (90)SP2001-02 (01)P1-100 (14) P1-14 (70)J-16 (89)P1-35-1 (90)P1-38-4 (97)P1-100 (14) P1-16 (78)J-16 (89)P1-35-2 (93)P1-100 (14) P1-20 (93)P1-42 (96)J-35-2 (96)P1-38-2 (97)J-33-2 (98)P1-43 (00)P1-46-2 (00)P1-71 (11) J-17 (92)J-17-2 (96)SP1995-67 (98)J-88 (05)J-57 (00)FE04-15 (04)FE05-26 (05)FE07-08J-96 P1-2 (59)PW-061 (80)PW-061R-1 (87)P1-38-4 (93)P1-100 (14) P1-34-1 (92)P1-38-2 (93)1-4-2 P1-9-11-4-2B P1-9-1 (74)P1-19 (82)P1-21 (88)P1-34-2 (91)P1-43 J-13 (74)PW-070 (79)J-13-2R (80)P1-43 (00)J-16 (89)J-108 (12) J-12 (71)J-16 (89)P1-44-3 (96)J-17-2 (96)SP1999-22 (01)SP2000-22 (01)SP2001-02 (01)FE05-33 (05) P1-11 (74)PW-074 (79)P1-18 (82)P1-24 (86)P1-24R (86)P1-23R (89)P1-38-4 (97)P1-38-2 (97)P1-37 (10)P1-33 (89) P1-5 (62)PW-061 (80)P1-18 (82)PW-061R-1 (87)P1-38-4 (97)P1-100 (14) J-5A (62)J-5C (62)J-5B (63)P1-8 (63)P1-16 (78)P1-22 (88)SP1995-72 (96)P1-38-4 (97)J-96 PW-144 (87)P1-33 (92)P1-42 (96)P1-40-2 (00)P1-37 (10)FE03-24 P1-25 (90)P1-33 (92)P1-38-2 (97)P1-38-4 (97)P1-46-2 (00)P1-43 (00)J-71-7 (00)P1-37 (10) J-23-1 (93)J-23-2 (95)J-17-2 (96)P1-40-2 (00)P1-48 (00)J-57 (00)P1-37 (10)J-79-1 (12)J-108 (12)FE05-32FE07-08FE09-17 P1-11 (64)PW-134 (86)P1-24R (86)P1-25 (90)P1-38-2 (93)P1-41-1 (94)P2-48 (00)FE06-03 (06)P1-37 (10)FE06-03 P1-34-1 (92)P1-34-3 (93)J-17-2 (96)SP1995-76A (96)P1-43 (00)P1-100 (14) PW-085 (83)PW-085-1 (84)P1-38-2 (97)J-35 (00) I-7-3 (72)P1-27 (89)P1-27-1 (91)P1-27-2 (91)P1-46-1 (00)P1-51 (00)J-71-3 (06) P1-22 (88)P1-20 (90)J-19-1 (94)J-23-2 (95)J-17-2 (96)P1-44-1 (96)P1-38-4 (97)J-33-2 (98)P1-43 (00) P1-16 (78)J-16 (89)J-23-2 (91)P1-36-1 (93)P1-38-4 (93)J-19-1 (94)J-23-2 (95)SP1995-20 (96)P1-9 (64)P1-16 (78)P1-21 (88)P1-22 (88)J-16 (89)J-19-1 (94)P1-44-1 (96)J-17-2 (96)P1-43 (00)FE05-29 (05)J-33-1A (09)P1-100 (14) P1-19 (82)P1-19-2 (83)PW-107 (84)P1-21 (85)P1-34-2 (91)J-23-2 (95) P1-36-1 (93)J-19-1 (94)J-17-2 (96)P1-36-2 (00)P1-40-2R (00)P1-48 (00)J-57 (00)SP1996-49 (00) P1-20 (87)P1-34-1 (89)P1-34-3 (93)P1-42 (96)P1-38-2 (97)J-71-7 (00)P1-46-2 (00)J-53 (00)J-60 (00)P1-34 (00)SP2001-02 (01)FE02-08 (05) P1-1 (57)P1-1R-1 (72)PW-134 (86)P1-24R (86)P1-25 (90)P1-41-1 (94)P1-38-2 (97)P1-38-4 (97)P2-48 (00)P1-37 (10) P1-7-1 (62)P1-7-2 (94)P1-15 (71)P1-16 (78)P1-18 (82)P1-21 (88)J-16 (89) P1-3 (59)P1-4 (61)J-5C (62)P1-10 (63)I-7-2 (69)I-7-3 (72)P1-3-1 (72)P1-3-2 (82)P1-22 (88)J-16 (89)P1-44-1 (96)P1-38-4 (97)P1-38-4 (97)P1-46-2 (00)P2-48 (00)P1-71 I-8 (71)I-8-3 (75)PW-052 (77)PW-055 (77)PW-055-1 (78)P1-3-2 (82)PW-132 (85)2-10-1A (86)P1-27 (89)J-16 (89)J-24 (90)P1-20 (90)P1-34-1 (92) SECONDARYCLARIFIERNO. 27 SECONDARY CLARIFIERNO. 29 SECONDARYCLARIFIERNO. 31 SECONDARYCLARIFIERNO. 33 *SEJB-6 SECONDARYCLARIFIERNO. 32 SECONDARY CLARIFIERNO. 34 *SEJB-7 ENGINEERING TRAILER D EAST 66KVOPERATINGBUS ENGINEERINGTRAILER F ENGINEERINGTRAILER E *GWRS METERVAULT GWRSSCREENINGFACILITIES *WSSPS NO. 2 DAFT1 DAFT2 DAFT3 DAFT4 DAFT5 DAFT6 WASTE SLUDGETHICKNERS (DAFT)PUMP ROOM BLEACH STATION *RAS BLEACH STATION AERATION BASINS11-18 BLOWER BUILDING *PEPS-2 JB PRIMARYCLARIFIERS16-31 *PB 7 TRUCK WASHSTATION DEWATERING BED NO. 3 DEWATERINGBED NO. 2 DEWATERINGBED NO. 1 SAWDUSTSTORAGE SLUDGE/SCUMPUMP STATION *PB 8 TRICKLINGFILTER PUMPSTATION *PB 1 STEVE ANDERSONLIFT STATION *PBNO. 9 SECONDARYCLARIFIERELECTRICALBUILDING ELECTRICALROOM P1-102 (11) P1-102 (11) P1-102 (11) P1-102 (11)P1-102 (11) P1-102 (11)P1-102 (11) P1-102 (06) P1-76 (09)J-36 (11) P1-102 (11) P1-102 (11) *PEDB P1-102 (11) I-10B (11) J-7 (64)J-7-1 (68)J-7-2 (71)J-7-3 (76)J-7-3A (77)J-7-3B (79)PW-088 (81)J-7-4 (92)P1-38-1 (93)FE08-01 (08)P1-37 (10) NORTH WALLJ-108 (12) J-35-2 (96)P1-44-1 (96)P1-38-2 (97)P1-38-4 (97)P1-46-2 (00)J-24 (00)P1-43 (00)P1-62 (00)PW-086 (00)SP2001-02 (01)J-71-1 (02)J-71-2 (02) J-108 (12)J-17-2 (96)SP1995-55 (99)J-57 (00)P1-48 (00)P1-44-4 (00)SP2001-02 (01)FE05-17FE07-08J-96 PW- 066-2 (90)J-23-2 (95)P1-44-4 (00)P1-43 (00)J-71-3 (06)P1-101P1-76 (09) *JB-5 *JB-4 *RAS PUMP STATION P1-76 (09)P1-37 (10)FE07-29 (08) P1-76 (09) P1-37 (10)FE06-02 (07) P1-106 (09)P1-101 P1-106 (09)P1-101 P1-106 (09)P1-101 P1-106 (09)P1-101 P1-102 (11) FE05-32 (05)J-79-1A (08)J-33-1A (09)P1-37 (10)P1-97 (11)J-79-1 (12)P1-100 (14)FE05-19 P1-22 (88)J-33-1A (09) J-87 (02)P1-102 (11)P1-76 SECONDARY CLARIFIERS25 & 26 P1-82 (11)J-36 (11) P1-18 (82)P1-22 (88)J-16 (89)J-17-2 (96)P1-46-2 (00)P1-82 (11) P1-16 (78)P1-18 (82)J-16 (89)J-17-2 (96)P1-36-2 (00)SP-94 (07)J-33-1A (09)FE02-23 (02)FE02-54 (02)P1-102 (11) J-36 (11) *PEJB *JB-C *TFEB *JB-3 *JB-B TFSE JB-2 *JB-A *SEJB-1 *SEJB-4 *SEJB-5 *TFSE JB-1 P1-97 (11) DISTRIBUTIONBOX *SEJB-2 SCRUBBERS 9 & 10 P1-38-2 (97)J-35 (00)J-71-7 (00) SLUDGE FEED PUMPSP1-21 (88) J-36 (11) J-36 (11) FUTURE SECONDARYCLARIFIERNO. 28 FUTURE SECONDARYCLARIFIERNO. 30 66"INTER I-4R 120"INTERI-9 84"INTER I-6-1 P1-51 (00)P1-44-4 (00)P1-36-2 (00)J-33-1A (09)P1-82 (11)P1-102 (11)FE04-43 P1-43 (00)P1-44-3 (96) J-23-1 (93) CART BUILDING P1-38-4 (97)P1-44-4 (00)P1-43 (00)J-71-3 (06)P1-101 POLYMER THICKENERFACILITYP1-36-2 (00) DIGESTERS 11-14 PUMP ROOM DIGESTERS 9 & 10PUMP ROOM DIGESTERS 15 & 16PUMP ROOM PRIMARYCLARIFIERS 3 & 4PUMP ROOM DIGESTERS7 & 8PUMP ROOM REVERSEOSMOSISBUILDING BULK CHEMICAL STORAGE FACILITY REVERSEOSMOSISTRANSFERPUMPSTATION PRODUCTWATER/ BARRIERPUMPSTATION MICROFILTRATIONBUILDING MICROFILTRATIONSTRUCTURE P1-62 (00)FE02-15 (02)FE04-05 (04)FE05-30 (05)J-33-1A (09)P1-71 (11)J-79-1 (12)FE04-05FE05-30 OCWDADMIN MWDOCADMIN L A B DECARBINATIONBUILDING ! ! ! COMPRESSEDNG STATION PAD TRANSFORMER Sources: Esri, HERE, DeLorme, USGS, Intermap, increment P Corp., NRCAN, Esri Japan, METI, Esri China (Hong Kong), Esri (Thailand), MapmyIndia, © OpenStreetMap contributors, and the GIS User Community Job Index Map o 0 120 240 360 48060Feet LABELS INDICATE STRUCTURE NAMERED BLUE LABELS INDICATE JUNCTION BOX NAME LABELS INDICATE TUNNEL NAMES Map prepared by Orange County Sanitation District.This map is intended for graphical representation only. No levelof accuracy is claimed for the base mapping shown hereon and graphics should not be used to obtain coordinate values, bearings or distances. Portions of this derived product contain geographicalinformation copyrighted by Thomas Brothers. All Rights Reserved. DISCLAIMER Source:OCSD GIS Data, Blue Book (CIP Database), Drawing Access System, Thomas Brothers 2010, ABBREV O C S D UPDATED: JANUARY 2017 GOLD & BLACK # # ! ! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! GROUND WATER REPLINISHMENT SYSTEM JUNCTION BOX POWER BUILDING PRIMARY EFFLUENT DISTRIBUTION BOX PRIMARY EFFLUENT JUNCTION BOX PRIMARY EFFLUENT PUMP STATION RETURN ACTIVATED SLUDGE SECONDARY EFFLUENT JUNCTION BOX TRICKLING FILTER EFFLUENT BOX TRICKLING FILTER SECONDARY EFLUENT WASTE SIDESTREAM PUMP STATION *GWRS *JB *PB *PEDB *PEJB *PEPS *RAS *SEJB *TFEB *TFSE *WSSPS DESCRIPTION ! ! ! ! ! Reclamation Plant 1 WHITE & BLACK LABELS INDICATE OCWD STRUCTURE NAME BLACK & WHITE LABELS INDICATE PROJECT NUMBER ! LEGEND OCSD STRUCTURES OTHER STRUCTURES STRUCTURES INCLUDED IN STUDY (BUILT BEFORE 2001) STRUCTURES NOT INCLUDED IN STUDY BUT BUILT BEFORE 2001 DIGESTERS 5 AND 6 PUMP ROOM DIGESTERS 7 AND 8 PUMP ROOM DIGESTERS 9 AND 10 PUMP ROOM DIGESTERS 11 THROUGH 14 P1-2 (59)P1-9 (64)P1-16 (78)P1-34-3 (93) J-5C (62)P1-14 (70)P1-18 (82)J-38-2 (97) PW-061 (80)P1-18 (82)P1-35-2 (93)J-57 (00) P1-18 (82)P1-35-1 (90)J-23-2 (95)P1-100 (14) PW-061R-1 (87)P1-100 (14)P1-100 (14) P1-21 (88) J-23-2 (95) P1-38-2 (97) P1-100 (14) DIGESTERS 15 AND 16 PRIMARY CLARIFIER 3-4 PUMP ROOM P1-34-3 (93)P1-1 (57) P1-100 (14)J-5C (62) P1-1R-1 (72) P1-18 (82) PW-104 (85) P1-24R (86) PW-134 (86) PUMP ROOM PROJECT LIST PS15-06 TM4 Appendix C 94 Orange County Sanitation District PS15-06 TM4 Appendix C 95 \Mtg Minutes - OCSD 10-11-17 MEETING MINUTES SUBJECT: PS15-06 Plant 2 Workshop DATE: Wednesday, October 11, 2017 TIME: 10:00 a.m. PST LOCATION: OCSD Plant 2, Ops Center Training and Conference Room MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering, Doug Lanning InfraTerra – Ahmed Nisar, Nikolay Doumbalski OCSD – Don Cutler, Mike Lahlou, Jeff Mohr, Eros Yong, Nasrin Nasrollahi, Tony Lee, Martin Dix 1. Safety Moment a. Presented by Chris Conkle b. Topic: Strokes 2. Meeting Objectives 3. Introductions a. Mr. Conkle introduced Geosyntec’s team 4. Review Project Background/Objectives 5. Review Project Approach 6. Geotechnical Hazard Primer 7. Task 1 – Background Development Update a. Geotechnical Conditions at Plant 2 PS15-06 TM4 Appendix C 96 PS15-06 Plant 2 Workshop Minutes October 11 2017 Page 2 i. P2-98 will be available within a few weeks. ii. Upcoming fault study evaluation. b. Structural Information at Plant 2 i. There’s a lot of information on P2-89 regarding some of the DAFTs. Looked at structural issues, but not at the soil issues. 8. Stakeholder Input – Plant 2 a. MAC building is currently empty, but connected to PEPS building. It may be used for storage or other maintenance function. 9. Q&A Q: Do we need to look at outfalls as part of this study? A: The group decided that outfall didn’t need to be included in the study. Q: Can we get a condition assessment for structures that don’t currently have them? Can reliability group develop them? A: A meeting with the corrosion/condition assessment engineers will be scheduled Q: Can gas holder be Class II? They can run the gas compressor directly if necessary. A: Could potentially make it Class II, but best to keep it Class I. Q: How do the analyses we do and the “regional” geohazards we develop provide qualitative input on other facilities that are not in scope? A: The study will give OCSD a good idea of the vulnerabilities at the plants. This will inform some of the planning associated with non-15-06 projects. PS15-06 TM4 Appendix C 97 PS15-06 Plant 2 Workshop Minutes October 11 2017 Page 3 10. Other Discussion Items a. What are operational lessons from other earthquakes? How long does it take to get back online? b. Include on section on Summary Sheet for other influenced structures. c. OOBS building probably needs to be added to the building list, critical to water in/water out. d. Truck loading needs to move to Class I. e. There hasn’t been significant emergency repair planning by the Engineering department. * * * * * Attachments • PowerPoint slides from OCSD Presentation 10-11-17 • Meeting handout: OCSD PS15-06 Task 1 to 4 Approach Flowchart • Meeting handout: Structures Data Gap Summary • Meeting handout: Plant 2 Structures for Seismic Evaluation Map • Meeting handout: Plant 2 Hydraulic Flow Diagram • Meeting handout: Scope of Work - Attachment 1, Proposed Structures Classification and Proposed Seismic Evaluation Approach PS15-06 TM4 Appendix C 98 Orange County Sanitation District Orange County Sanitation District PLANT 2 WORKSHOP SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 PS 15-06 | OCTOBER 11, 2017 PS15-06 TM4 Appendix C 99 Orange County Sanitation District Safety Moment: Strokes -“Time is Brain” •For every hour without treatment, the brain effectively ages by 3.6 years •Stoke Causes •caused by a clot (85%) •burst blood vessel (15%) •Use tissue plasminogen activator (tPA ) to dissolve a clot •UCLA and the City of Santa Monica Fire Department -first mobile stroke unit in California •Mobile CT Scanner / Telemedicine •Shorten treatment time from 3 hours to 90 mins •Remember “FAST” to get treatment started 2 Ed Yong: First response: Race against time Nature 510, S5 (26 June 2014) PS15-06 TM4 Appendix C 100 Orange County Sanitation District Safety Moment: Strokes -“Time is Brain” 3 PS15-06 TM4 Appendix C 101 Orange County Sanitation District Agenda •Safety Moment •Meeting Objectives •Introductions •Review Project Background/Objectives •Review Project Approach •Geotechnical Hazard Primer •Task 1 –Background Development Update •Geotechnical Conditions at Plant 2 •Structural Information at Plant 2 •Stakeholder Input –Plant 2 4 PS15-06 TM4 Appendix C 102 Orange County Sanitation District Meeting Objectives •Gather information regarding particular concerns at Plant 2 •Illustrate the project approach at Plant 2 •There are hazards –need smart solutions •TM1 approach that meets OCSD needs 5 PS15-06 TM4 Appendix C 103 Orange County Sanitation District Introductions OCSD •Don Cutler –Project Manager •Mike Lahlou –Project Engineer •Jacobs (Technical Review) Geosyntec •Chris Conkle –Project Manager •Chris Hunt –Project Director/Hazards Carollo •James Doering –Vulnerability •Doug Lanning –Strategic Planning InfraTerra •Ahmed Nisar –Alternatives & Recommendations 6 PS15-06 TM4 Appendix C 104 Orange County Sanitation District Plant 1 Stakeholders 7 Department Staff Div. Planning Kathy Millea/Eros Yong 740 Engineering Dean Fisher/Martin Dix/ Mike Dorman 760 and 770 Operations Jon Bradley/Tony Lee/ Umesh Murthy 830 and 840 Maintenance Jed Gonzales/Don Stokes 870 and 880 Risk Rich Spencer 161 PS15-06 TM4 Appendix C 105 Orange County Sanitation District Project Background •Recognized potential for structural and geo-seismic vulnerabilities •An overall system wide approach is needed for identifying and addressing deficiencies 8 PS15-06 TM4 Appendix C 106 Orange County Sanitation District Seismic Sources 9 20 % 5%4% 1% 3% Mean 30-Year (2014 –2044) Probabilities of M >= 6.7 UCERF3 (USGS, SCEC) PS15-06 TM4 Appendix C 107 Orange County Sanitation District Sloshing damage to sludge scraper chain rail at Tillman water reclamation plant, Van Nuys –1994 Northridge Earthquake Broken Tie-Down Straps – Larwin Tank; 1994 Northridge Earthquake Gas holding tanks in Oshamanbe area on soft soils were not damaged but the underground piping was damaged by ground settlement –1995 Hokkaido Earthquake Damaged water stop in aeration basin –1995 Kobe Earthquake Damage to scraper chain in sedimentation tanks –1995 Kobe Earthquake Wood baffles afloat after being dislodged by sloshing at a water treatment plant – 1964 Nigata Earthquake Waste Water Systems Past Earthquake Performance PS15-06 TM4 Appendix C 108 Orange County Sanitation District Gas holder (2,300 cu. m.) inclined about 4-inches as “Nuttari” area –1964 Nigata Earthquake Sedimentation basin of the “Tamongawa” pumping station was broken at the center –1964 Nigata Earthquake Wood baffles damaged by sloshing at a water treatment plant –1964 Nigata Earthquake Damage to overhead bridge – 1964 Nigata Earthquake Waste Water Systems Past Earthquake Performance PS15-06 TM4 Appendix C 109 Orange County Sanitation District Project Objectives •Overall PS15-06 •Develop system for addressing these vulnerabilities going forward •Apply this procedure to select structures first •Understanding of site geo-seismic hazards –Task 2 •Efficient structural assessments –Task 3 •Combined approach to the geotechnical and structural aspects to develop mitigation options/costs –Task 2/3 •Seismic CIP & Implementation Plan •Project Planning Level Costs •Project Prioritization 12 PS15-06 TM4 Appendix C 110 Orange County Sanitation District What is the Overall Vision? 13 PS15-06 TM4 Appendix C 111 Orange County Sanitation District 14 PS15-06 Project Report Evaluation of Other System Components (Piping, Electrical, etc.) PS15-06 Seismic CIP / Implementation (Vulnerable Structures) Understanding of Broader Site Issues (Geotechnical/ Structural) Future CIPs on Non PS15-06 Facilities Produces PS15-06 Prior Studies Prior Projects Produces Geotechnical/ Structural Evaluations of Non PS15-06 Structures Outside PS15-06 Informs PS15-06 Outcomes PS15-06 TM4 Appendix C 112 Orange County Sanitation District 15 Project Approach PS15-06 TM4 Appendix C 113 Orange County Sanitation District •Ground Shaking •Other Effects •Liquefaction •Lateral Spreading •Surface Fault Rupture (Plant 2) Seismic Hazards to be Evaluated? 16 Gas holder (2,300 cu. m.) inclined about 4- inches in “Nuttari” area –1964 Nigata Earthquake PS15-06 TM4 Appendix C 114 Orange County Sanitation District •Cause of other hazards •Need to understand characteristic of ground motions •Effects of site conditions on shaking •Consider the effects of numerous sources/events •Amplitude of Shaking •Peak Ground Acceleration (PGA) •Most Common Measure •Frequency •Structures are very sensitive to frequency of loading •Soil Deposits act as filters Ground Shaking 17 PS15-06 TM4 Appendix C 115 Orange County Sanitation District Ground Shaking 18 Source: GARINI, E and GAZETAS, G “M 7.1 Puebla (Mexico) 19-9-17 Earthquake: A near “repeat” of the M 8.1 Earthquake of 1985 that had devastated Mexico City (19 000 deaths)” Preliminary Report Dated: 25 September 2017 PS15-06 TM4 Appendix C 116 Orange County Sanitation District Ground Shaking 19 Source: GARINI, E and GAZETAS, G “M 7.1 Puebla (Mexico) 19-9-17 Earthquake: A near “repeat” of the M 8.1 Earthquake of 1985 that had devastated Mexico City (19 000 deaths)” Preliminary Report Dated: 25 September 2017 T=1.4 sec –Natural Period of 5-10 sty structure PS15-06 TM4 Appendix C 117 Orange County Sanitation District Ground Shaking 20 PS15-06 TM4 Appendix C 118 Orange County Sanitation District •Generation of excess pore pressures under cyclic loading •Contractive Response •Rapid Loading -“Undrained” •Leads to softening of soils Liquefaction 21 LiquefactionWater’s ResponseEarthquakeLoose Soil PS15-06 TM4 Appendix C 119 Orange County Sanitation District Liquefaction 22 PS15-06 TM4 Appendix C 120 Orange County Sanitation District •Liquefaction Effects •Level Ground Liquefaction -settlement of buildings, retaining wall failure •Lateral Spreading Liquefaction 23 PS15-06 TM4 Appendix C 121 Orange County Sanitation District Liquefaction Effects 24 Level Ground Liquefaction –Ground Oscillation •Effects: settlement of buildings, retaining wall failure PS15-06 TM4 Appendix C 122 Orange County Sanitation District Lateral Spreading 25 PS15-06 TM4 Appendix C 123 Orange County Sanitation District Lateral Spreading –Plant 1 26 PS15-06 TM4 Appendix C 124 Orange County Sanitation District •Is soil susceptible to liquefaction? •Can liquefaction be triggered? •If triggered, will damage occur? •What remediation is required? Liquefaction Evaluations 27 PS15-06 TM4 Appendix C 125 Orange County Sanitation District Surface Fault Rupture –Plant 2 28 •Use best available existing hazard information to identify affected structures •From Previous Studies •Estimate the magnitude of the hazard •From Previous Studies •Develop appropriate offset demand for structures • PS15-06 •Evaluate retrofit options to address the combined seismic hazards • PS15-06 Bray and Oettle, 2012PS15-06 TM4 Appendix C 126 Orange County Sanitation District Surface Fault Rupture –Plant 2 29 •General Mitigation Strategies •Diffuse rupture with ductile fill or soil •Create rigid body movement with thick mat foundation and isolation •Divert / deflect movement with ground improvement, subsurface walls, anchors, etc. •Retrofit structure to handle max soil loads without failing Source: GEER / NSF M7.0 Kumamoto Earthquake Reconnaissance (Oettle, 2016) PS15-06 TM4 Appendix C 127 Orange County Sanitation District Surface Fault Rupture –Plant 2 30 •Mitigation Strategies PS15-06 TM4 Appendix C 128 Orange County Sanitation District Task 1 –Background Review –Plant 2 31 PS15-06 TM4 Appendix C 129 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 2 32 PS15-06 TM4 Appendix C 130 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 2 33 PS15-06 TM4 Appendix C 131 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 2 34 PS15-06 TM4 Appendix C 132 Orange County Sanitation District Task 1 –Example Structural Summary 35 PS15-06 TM4 Appendix C 133 Orange County Sanitation District Task 1 –Example Structural Summary 36 PS15-06 TM4 Appendix C 134 Orange County Sanitation District Task 1 –Structural Evaluations 37 •Review Available Structural Information •Drawings •Specifications •Corrosion Assessment Reports •Seismic Evaluation Reports •Site Visit •Identify Data Gaps PS15-06 TM4 Appendix C 135 Orange County Sanitation District Task 1 –Background Review – Structural Information 38 Non-process Buildings Process Buildings Misc Structures Basins & Clarifiers Digesters / DAFTs . PS15-06 TM4 Appendix C 136 Orange County Sanitation District Task 1 –Site Visit–Plant 2 39 PS15-06 TM4 Appendix C 137 Orange County Sanitation District Task 1 –Site Visit–Plant 2 40 PS15-06 TM4 Appendix C 138 Orange County Sanitation District Task 1 –Structural Evaluations 41 •Review Available Structural Information Review Project Drawings for Original Construction Request/Search for Additional Information Any missing information ? Identify Data Gaps PS15-06 TM4 Appendix C 139 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 42 Central Generation OOBS PS15-06 TM4 Appendix C 140 Orange County Sanitation District Task 1 –Geotechnical Evaluations –Plant 2 43 PS15-06 TM4 Appendix C 141 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 44 PS15-06 TM4 Appendix C 142 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 45 PS15-06 TM4 Appendix C 143 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 46 •Potential Failure Modes to Investigate –Structural Pounding 6” GAP OOBSCentral Generation PS15-06 TM4 Appendix C 144 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 47 PS15-06 TM4 Appendix C 145 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 48 •Potential Failure Modes to Investigate –Wall Anchorage PS15-06 TM4 Appendix C 146 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 49 •Potential Failure Modes to Investigate –Liquefaction / Settlement Central Generation OOBS Potential for rigid differential rotation and/or lateral spread PS15-06 TM4 Appendix C 147 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 50 •Potential Failure Modes to Investigate – Seismic soil load on basement walls PS15-06 TM4 Appendix C 148 Orange County Sanitation District Task 1 –Structural Evaluations –Plant 2 Central Generation 51 •Practical considerations What is the consequence? Will the consequence impair performance? PS15-06 TM4 Appendix C 149 Orange County Sanitation District Review Structure List Plant 2 –OCSD Input 52 PS15-06 TM4 Appendix C 150 Orange County Sanitation District Review Structure List Plant 2 –OCSD Input 53 PS15-06 TM4 Appendix C 151 Orange County Sanitation District Review Structure List Plant 2 –OCSD Input 54 ID Number Structure Name Plant Facility Class Type Original Project Additional Projects Condition Assessment Basis Structural Data Gaps Level 1 Level 2 2-1 DAFT A, B, & C Gallery 2 I Building P2-23-6 P2-42-2 Site Visit Post-tensioned anchor info 2-2 DAFT D Gallery & WSSPS 2 I Building P2-42-2 Site Visit 2-3 RAS PS East 2 I Building P2-23-6 Site Visit Post-tensioned anchor info 2-4 RAS PS West 2 I Building P2-23-6 Site Visit Post-tensioned anchor info 2-5 PEPS & MAC 2 I Building P2-23-6 P2-23-2 Site Visit Post-tensioned anchor info Condition assessment of PEPS 2-6 Operations/Control Center Bldg 2 I Building P2-23-5 Site Visit Roof decking 2-7 12 kV Service Center 2 I Building P2-23-3 Site Visit Roof decking 2-8 Power Building B 2 I Building P1-15 P2-24-2 Site Visit Roof decking 2-9 Power Building C 2 I Building P2-24-1 J-6-2 Site Visit 2-10 Power Building D 2 I Building J-6-2 Site Visit 2-11 City Water Pump Station 2 I Building P2-46 Site Visit 2-12 12 kV Distribution Center B 2 I Building P2-23-6 P2-23-2 Site Visit Post-tensioned anchor info 2-13 12 kV Distribution Center D 2 I Building P2-35-3 Site Visit 2-14 Headworks Power Bldg A 2 I Building P2-37 J-33-1 Site Visit 2-15 Headworks Power Bldg B 2 I Building P2-42-1 J-33-1 Site Visit 2-16 Headworks Standby Power Building 2 I Building J-33-1 Site Visit 2-17 Central Power Generation Building 2 I Building J-19-2 J-15 Site Visit 2-18 Aeration Basins A-H 2 I Tank P2-23-6 P2-23-2 Condition Assessment Report for Basins A and H Post-tensioned anchor info 2-19 Gas Holder 2 I Steel Tank P2-24-1 Condition assessment 2-20 Secondary Clarifiers A-L 2 I Tank P2-23-6 P2-42-2 Post-tensioned anchor info Condition assessment 2-21 DAFTs A-C 2 I Tank P2-23-6 Condition Assessment Report for DAFT C / Site Visit for DAFT out of service Aluminum dome shop drawings 2-22 DAFT D 2 I Tank P2-42-2 Condition Assessment Report for DAFT C / Site Visit for DAFT out of service Prefabricated dome shop drawings 2-23 Surge Tower No. 1 2 I Tank J-34-1 Condition Assessment Report for Surge Tower No. 2 Pile info 2-24 Surge Tower No. 2 2 I Tank J-9 J-34-1 Condition Assessment Report for Surge Tower No. 2 Structural drawings for steel extension after J-34-1 / Condition assessment 2-25 Effluent Junction Structure 2 I Tank J-3 Condition Assessment Report for Effluent Junction Structure Condition assessment 2-26 Maintenance Building 2 II Building P2-35-3 Site Visit 2-27 Boiler Building 2 II Building P2-17 Site Visit 2-28 Truck Loading 2 II Tank P2-60 Condition assessmentPS15-06 TM4 Appendix C 152 Orange County Sanitation District Action Items/Summary 55 •Incorporate OCSD input into Approach •Next Workshop TM1 –10/25/17 •TM1 Draft –10/31/17 PS15-06 TM4 Appendix C 153 Orange County Sanitation District Thank You! 56 PS15-06 TM4 Appendix C 154 OCSD Seismic Evaluation Document Review Request Documents Data Gaps? Plan Investigation / Site Visits Structure Classification / Reclassification Tech Memo 1 Field Gaps Doc Gaps OK Task 1 Geotechnical Investigation Structural Site Visits Key Structure? Site Response Analysis Response Spectra Seismic Inputs Evaluate Ground Deformations Geotechnical Analyses Site Model Settlement Foundation Type/Capacity Lateral Spread Fault Rupture Information Flow Direction Structural Input to Geotech Task 2 Task 3 Def. OK? Cost Estimates Ground Improvement Measures Tech Memo 2 No No Yes Data Gaps? As-Built Survey & Non-Destructive Testing Yes Structural Evaluation No Building Structures Liquid Containing Structures Geotech Input to Structural ACI 350.3 Analysis ASCE 41-13 Tier 1 Ground Def. OK? Ground Def. OK? Yes Perform. OK? Perform. OK? Structure Deformation Outputs Yes No ASCE 41-13 Tier 2 Perform. OK? FE Analysis Warranted? No No Finite Element / Tier 3 Analysis No No Strengthening / Retrofit Improvements Yes Yes Perform. OK? No Cost Estimates Tech Memo 3 Yes Yes Compile TM 1-3 Information Task 4 Incorporate Mitigation Measures Evaluate Criticality & Consequence Develop Risk Ranking Criticality, Consequences & Ranking Appropriate? Tech Memo 4 Yes No Background Development Geotechnical Evaluation Structural Evaluation Criticality & Ranking OCSD PS15-06 Task 1 to 4 Approach Flowchart 8 October 2017 Yes PS15-06 TM4 Appendix C 155 Level 1 Level 2 2-1 DAFT A, B, & C Gallery 2 I Building P2-23-6 P2-42-2 Site Visit Post-tensioned anchor info 2-2 DAFT D Gallery & WSSPS 2 I Building P2-42-2 Site Visit 2-3 RAS PS East 2 I Building P2-23-6 Site Visit Post-tensioned anchor info 2-4 RAS PS West 2 I Building P2-23-6 Site Visit Post-tensioned anchor info 2-5 PEPS & MAC 2 I Building P2-23-6 P2-23-2 Site Visit Post-tensioned anchor info Condition assessment of PEPS 2-6 Operations/Control Center Bldg 2 I Building P2-23-5 Site Visit Roof decking 2-7 12 kV Service Center 2 I Building P2-23-3 Site Visit Roof decking 2-8 Power Building B 2 I Building P1-15 P2-24-2 Site Visit Roof decking 2-9 Power Building C 2 I Building P2-24-1 J-6-2 Site Visit 2-10 Power Building D 2 I Building J-6-2 Site Visit 2-11 City Water Pump Station 2 I Building P2-46 Site Visit 2-12 12 kV Distribution Center B 2 I Building P2-23-6 P2-23-2 Site Visit Post-tensioned anchor info 2-13 12 kV Distribution Center D 2 I Building P2-35-3 Site Visit 2-14 Headworks Power Bldg A 2 I Building P2-37 J-33-1 Site Visit 2-15 Headworks Power Bldg B 2 I Building P2-42-1 J-33-1 Site Visit 2-16 Headworks Standby Power Building 2 I Building J-33-1 Site Visit 2-17 Central Power Generation Building 2 I Building J-19-2 J-15 Site Visit 2-18 Aeration Basins A-H 2 I Tank P2-23-6 P2-23-2 Condition Assessment Report for Basins A and H Post-tensioned anchor info 2-19 Gas Holder 2 I Steel Tank P2-24-1 Condition assessment 2-20 Secondary Clarifiers A-L 2 I Tank P2-23-6 P2-42-2 Post-tensioned anchor info Condition assessment 2-21 DAFTs A-C 2 I Tank P2-23-6 Condition Assessment Report for DAFT C / Site Visit for DAFT out of service Aluminum dome shop drawings 2-22 DAFT D 2 I Tank P2-42-2 Condition Assessment Report for DAFT C / Site Visit for DAFT out of service Prefabricated dome shop drawings 2-23 Surge Tower No. 1 2 I Tank J-34-1 Condition Assessment Report for Surge Tower No. 2 Pile info 2-24 Surge Tower No. 2 2 I Tank J-9 J-34-1 Condition Assessment Report for Surge Tower No. 2 Structural drawings for steel extension after J-34- 1 / Condition assessment 2-25 Effluent Junction Structure 2 I Tank J-3 Condition Assessment Report for Effluent Junction Structure Condition assessment 2-26 Maintenance Building 2 II Building P2-35-3 Site Visit 2-27 Boiler Building 2 II Building P2-17 Site Visit 2-28 Truck Loading 2 II Tank P2-60 Condition assessment Notes OCSD - PS15-06 - Structure Data Gap Summary Structural Data Gaps ID Number Structure Name Plant Facility Class Type Original Project Additional Projects Condition Assessment Basis PS15-06 TM4 Appendix C 156 S A N T A A N A R I V E R T A L B E R T M A R S H CA R N E Y RICHA R D S HARRI S HUNT HU N T CA N T R E L L RO L L I N S LEWIS SLOU G H BIL L I N G LIN D S T R O M BRER E T O N PFLAN Z RI B A L BRER E T O N FR E I S E N FLORE S KINNIS O N HA Z E L HA Z E L SC O T T PA R K E R LA N D O N TREM B L A Y EL L A KINNI S O N HARRI S IR E N E VO R M I T A G MU R P H E Y MARC O T T E KINNI S O N SCOT T H E A D M A N LIN D S T R O M HEAD M A N KINNI S O N SCOTT MORR I S O N VO R M I T A G CONTRACTOR WORK AREA (TEMPORARY) B R O O K H U R S T S T R E E T BUSHARD A V E N U E EAS T P E R I M E T E R R O A D WEST P E R I M E T E R R O A D EAS T P E R I M E T E R R O A D M O R R I S O N A V E N U E B U S H A R D S T R E E T SOUTH P E R I M E T E R R O A D W E S T P E R I M E T E R R O A D PACIFI C C O A S T H I G H W A Y ACC E S S R O A D ( D I R T ) MO R R I S O N A V E N U E SOUTH P E R I M E T E R R O A D SP1999-65 (99)P2-65 (00) P2-55 (95)FE02-08 (05)P2-82 (08) P2-55 (00)FE02-08 (05)P2-82 (08) P2-23-5-1 (93)SP1995-35 (95)J-57 (00) J-16 (89)J-40-6 (05)P2-23-06 (83) P2-42-2 (96) P2-42-2 (93)PW-144 (87)P2-82 (08) P2-42-2 (93)P1-38-4 (97) J-32 (94)SP1995-10 (95)P2-49 (96) P1-38-5 (00)P2-35-3 (00)P2-46 (00) PW-045 (76)J-57 (00)P2-35-3 (03)SP-98SP1998-34R P2-37 (90)J-17-2 (96)P2-43-1 (96)P1-38-4 (97)J-33-1 (99)P2-50 (00)J-33-1A (09)P2-66 (14)J-17-2 P2-23-6 (83)J-16 (89)P2-37 (90)P2-46 (95)P2-42-2 (96)J-17-2 (96)P1-38-4 (97)P2-50 (00)SP-81 (08)P2-47-3 (08)P2-82 (08)J-33-1A (09)P2-74 P2-19 (72)PW-134 (86)P2-31R (87)J-16 (89)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (04)SP-73 P2-24-1 (82)P2-23-6 (83)P2-144 (87)J-16 (89)P2-37 (90)P2-42-2 (93)J-17-2 (93)P1-38-4 (93)P2-43-1 (96)P2-50 (00)P2-82 (08)J-33-1A (09)P2-91 P2-23-5 (79)PW-80 (80)PW-078 (80)PW-112 (84)PW-080 (84)P2-23-5-1 (93)J-17-2 (93)P2-37 (90)P2-53-3 (94)SP1998-15 (98)J-57 (00)J-33-1A (09)J-79-1 (11)FE02-62PW-149P2-55 P2-23-6 (83)P2-37 (90) P2-23-6 (83)P2-37 (90) P2-23-6 (83)P2-37 (90) P2-25-1A (83)P2-26 (85)J-6-2 (87)P2-53-3 (94)P2-50 (00)P2-65 (00)J-33-1A (09)P2-80 (11)J-17-2P2-144P2-91 J-4-1 (74)PW-043 (75)P2-28-1 (87)P2-46 (95)P1-38-4 (97) J-33-1 (99)FE05-34 P2-66 (14) I-4-2 (67)I-4-1R (77)I-9 (93) P2-42-2 (93) P2-55 (00)FE02-08 (05)P2-82 (08) P2-11-1 (74)J-34-1 (00)J-2 (00)SP200-61 P2-1 (54)P2-37 (90) P2-24-1 (82)J-16 (89) P2-16 (72)J-16 (89)P1-38-4 (97)P2-39 (00) PW-141 (85)P2-37 (90)P2-43-1 (96) M-044P2-46-1 (98)P2-66-2P2-70 (00) P2-23-2 (81)P1-38-4 (97) P2-24-1 (82)J-16 (89)P2-37 (90)P2-43-3 (93) J-3 (59)P2-2 (60)P2-16 (71)P2-18 (71)J-77 P2-1 (54)P2-37 (90) P2-14 (70)P1-38-4 (97)P2-39 (00) P2-17 (72)J-16 (89)P1-38-4 (97)P2-39 (00)P2-56 (00) P2-8-1 (66)J-9 (67)J-15B-1 (87)J-15B-2 (87)P2-42-2 (96)J-87 (03)J-77 (09)J-34-1SP2000-61 P2-21 (74)J-16 (89)P1-38-4 (97)P2-39 (97) P2-19 (72)P1-38-4 (93)P2-39 (97) P2-19 (72)P1-38-4 (93)P2-39 (97) P2-24-1 (82)J-16 (89)P2-37 (90)P1-38-4 (97)P2-43-3 (96)P2-24-1 (82)J-16 (89)P2-37 (90)P2-43-3 (96)P1-38-4 (97)P2-24-1 (82)J-16 (89)P2-37 (90)P2-43-3 (96)P1-38-4 (97) P2-21 (74)J-16 (89)P1-38-4 (97)P2-39 (00) J-6-2 (87)P1-38-4 (97)J-17-2 (96)P2-50 (00)P2-66 (14)R-033-2R P1-25 (90)P2-43-1 (96)P1-38-4 (97)P2-55 (00)J-71-7 (02)FE02-08 (05)P2-82 (08)J-67 P2-3 (63)P2-30 (87)P1-38-4 (97)P2-43-3 (96) P2-24-1 (82)J-16 (89)P2-37 (90)P1-38-4 (97)P2-43-3 (96) P2-5 (63)PW-134 (86)P2-5R-2 (86)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (03)SP-73 P2-4 (62)I-4-2 (67)P2-8-3 (69)P2-17 (72)J-79-1 (11)P2-24-1 (82)P2-23-6 (83)J-16 (89)P1-38-4 (97)P2-56 (00)P2-61 (00)SP2000-61 P2-1 (54)P2-11 (69)P2-1R-1 (72)P2-24-2 (82)P1-25 (90)P2-43-1 (96)P2-43-3 (96)J-67 P2-7 (65)PW-121 (84)J-21 (93)P2-56 (00) P2-42-1 (94)P1-38-4 (96)P2-43-1 (96)J-17-2 (96)J-33-1 (99)P2-50 (00)J-33-1A (09)P2-66 (14)FE05-34P2-47-2J-17-2 P2-23-2 (81)P2-23-6 (83)PW-115 (84)PW-123 (84)J-16 (89)P2-42-1 (94)P2-43-1 (96)P1-38-4 (97)J-40-6 (05)P2-47-3 (08)P2-66 (14)P2-74FE05-43 P2-1 (54)P2-8-1 (66)P2-12 (67)P2-20 (75)J-4-2 (79)P2-23-3 (79)PW-118 (85)J-6-2 (87)P2-31R (87)J-16 (89) P2-24-2 (82)P2-28-2 (86)P2-28-1 (87)PW-144 (87)J-16 (89)P2-37 (90)P1-43-3 (96)P1-38-4 (97)P2-60 (00)SP1995-03 P2-24-1 (82)PW-141 (85)PW-144 (87)J-16 (89)J-19-2 (90)P2-43-3 (96)P1-38-4 (97)P2-49 (96)J-33-1A (09)P2-47-2SP1999-38 P2-16 (71)PW-134 (86)P2-31R (87)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (03) J-19-2 (95)P2-51 (93)P2-49 (93)J-19-A (95)P2-43-1 (96)P1-38-4 (97)J-33-1 (99)J-57 (00)FE05-13 (04) P2-23-6 (83)PW-115 (84)J-16 (89)P1-38-4 (97)P2-49 (96)P2-42-2 (96)J-87 (03)J-40-6 (05)P2-74 P2-2 (60)P2-24-2 (80)PW-061 (80)PW-061R-2 (86)J-16 (89)P1-38-4 (97) P2-3 (63)PW-061 (80)P2-24-2 (80)PW-061R-2 (86)J-16 (89)P2-43-3 (96)P1-38-4 (97) P2-5 (63)P2-21 (74)P2-30 (87)P2-43-3 (96)P1-38-4 (97)P2-39-1 (00)J-5-1 (00) P2-26 (85)PW-134 (86)P2-31R (87)J-16 (89)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (03)SP-73SP2000-60 I-4-2 (67)P2-8-3 (69)PW-064A (79)P2-80 (11) P2-23-2 (81)P2-23-6 (83)P2-131 (84)PW-123 (84)P2-43-3 (96)P1-38-4 (97)P2-50 (00)P2-47-3 (08)P2-23-2 (81)J-16 (89)P2-23-6 (83)P2-42-1 (94)P2-53-3 (94)P1-38-4 (97)FE07-29P2-74 P2-7 (65)P2-7-1 (65)P2-8-3 (69)P2-23-3 (79)P2-24-1 (82)J-16 (89)P1-38-4 (97)P2-47-1 (00)P2-50 (00)R-027-1R-027-2R-003-2R P2-2 (60)PW-134 (86)P2-29 (86)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (04)SP-73 P2-23-3 (79)J-6-2 (87)J-16 (89)P2-37 (90)P2-49 (96)P2-43-1 (96)P1-38-4 (97)P2-47-1 (00)P2-50 (00)J-33-1A (09)J-79-1 (11)P2-66 (14) P2-27 (84)P1-25 (90)P2-37 (90)P2-43-1 (96)P1-38-4 (97)P2-55 (00)J-71-7 (00)P2-46-2 (00)P2-82 (08)J-33-1A (09)P2-47-24R P2-23-2 (81)P2-23-6 (83)PW-131 (84)J-16 (89)P2-37 (90)P2-42-1 (94)J-32 (94)P2-43-1 (96)J-17-2 (96)P1-38-4 (97) P2-19 (72)PW-134 (86)P2-31R (87)J-16 (89)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (04)SP-73 P2-26 (85)PW-134 (86)P2-31R (87)J-16 (89)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (03)SP-73SP2000-60 P2-25-1A (83)PW-134 (86)P2-31R (87)J-16 (89)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (03)SP-73 P2-25-1A (83)PW-134 (86)P2-31R (87)J-16 (89)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (03)SP-73 P2-1 (54)P2-23-6 (83)J-16 (89)P2-42-1 (91)P2-43-3 (96)P2-43-1 (96)P1-38-4 (97)P2-47-1 (00)P2-82 (08)J-79-1 (11)J-17-2J-19-2 P2-12 (67)PW-134 (86)P1-31R (87)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (04)SP-73 P2-3 (63)P2-29 (86)P1-25 (90)P1-41-1 (94)PW-134 (96)P1-38-4 (97)P2-48 (00)P2-85-1 (00)P2-85 (04)SP-73 J-16 (89)P2-23-6 (83)P2-37 (90)P1-38-4 (90)J-32 (94)P2-46 (95)P2-43-1 (96)J-17-2 (96)P2-42-2 (96)P2-50 (00)J-40-6 (05)P2-47-3 (08)P2-82 (08)J-33-1A (09)P2-74SP2000-61P2-14 (70)PW-134 (86)P2-31R (87)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-48 (00)P2-85 (04)FE05-43SP-73 J-15 (90)I-9 (93)P2-51 (94)P2-42-1 (94)P2-43-1 (96)J-17-2 (96)P1-38-4 (97)P2-56 (00)J-31-2 (00)P2-50 (00)P2-47-1 (00)J-87 (03)P2-82 (08)J-33-1A (09)J-79-1 (11)J-79-1AFE02-58J-67 P2-5 (63)PW-061R-2PW-061 (80)P2-24-2 (82)J-16 (89)P2-43-3 (96)P1-38-4 (97)J-5-1 (00)P2-39-1 (00)PW-061R-3SP-117 P2-16 (71)P2-17 (72)PW-134 (86)P2-31R (87)P1-25 (90)P1-38-4 (97)P2-48 (00)P2-85 (04)P1-25 P2-17 (72)PW-035 (75)P2-43-1 (96)P2-49 (96)P2-43-3 (96)PW-023 (00)P2-47-1 (00)P2-15 (00)J-79-1 (11)P2-80 (11) P2-5 (63)PW-134 (86)P2-5R-2 (86)P1-25 (90)P1-41-1 (94)P1-38-4 (97)P2-85-1 (00)P2-48 (00)P2-85 (04)P2-74SP-73 P2-5 (63)PW-061 (80)P2-24-2 (82)PW-061R-2 (86)J-16 (89)P2-43-3 (96)P1-38-4 (97)P2-39-1 (00)J-5-1 (00)PW-061R-3PW-061R-4SP-117 P1-15 (71)P2-24-1 (82)P2-24-2 (82)PW-115 (84)PW-144 (87)P2-28-1 (87)P2-37 (88)J-16 (89)P2-43-1 (93)P1-38-4 (93)P2-53-3 (94)P2-43-3 (96)P2-56 (00)P2-39 (00)P2-15-1 (00)P2-60 (00)P2-82 (08)SP1995-03 P1-15 (71)P2-17 (72)P2-19 (72)P2-21 (74)PW-035 (75)P2-23-3 (79)P2-24-1 (82)P2-25-1A (83)P2-28-2 (86)PW-061R-2 (86)P2-28-1 (87)J-6-2 (87) P2-66 (14) P2-66 (14) P2-66 (14) P2-66 (14) P2-66 (14) P2-66 (14) P2-66 (14) P2-66 (14) P2-66 (14)P2-90 (11) P2-66 (14) P2-66 (14) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11)P2-90 (11) P2-90 (11) P2- 9 0 ( 1 1 ) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11) P2-90 (11) P2-66 (14) P2-8-6 (70)P2-8-7 (70)PW-125 (00)P2-35-5 (00)SP2000-03 (00)SP1998-15 P2-37 (90)P2-40 (00)P1-25 (90)P2-43-3 (96)PW-023 (72)P2-82 (08)J-16P2-66 (14) P2-47-1 (98)P2-50 (00)P2-47-3 (08)SP-81 (08)J-33-1A (09)P2-47-2J-34-1P2-74P2-47-2RP2-91 P1-38- 4 ( 9 7 ) J-77 (0 9 ) J-4 (62)P2-17 (72)J-4-1 (74)J-4-2 (79)J-4-2-1 (83)PW-085 (83)PW-110 (84)PW-123 (84)PW-085-1 (85)J-16 (89)P2-37 (90)P2-43-1 (93)P2-55 (00)J-5-1 (00)J-87 (03) J-33-1A (09)J-79-1 (11)P2-66 (14)P2-47-2FE04-45RJ-79-1A J-17-2J-67 P2-60 (00) P2-35-3 (95)P2-60 (00)SP-81(08)P2-66 (14) J-77 (09)J-77 (09) P2-66-2 PW-118 (85)PW-132 (85)P2-43-1 P2-82 (08) P2-17 (72) J-16 (89)P2-53-3 (94)P2-49 (96)J-17-2 (96)P2-39 (00)P2-50 (00)P2-47-1 (00)P2-15 (00)P2-60 (00)J-57 (00)J-33-1A (09)P2-80 (11)J-19-2 P2-49 (96)P2-43-1 (96)J-17-2 (96)P2-50 (00)J-5-1 (00)P2-61 (00)J-33-1A (09)J-77 (09)P2-80 (11)J-67 P2-91 P2-24-1 (82)P2-37 (88) P2-91 P2-1R-1 (72) J-77 (09) I-4-2 (67)P2-2 (60)P2-39 (00)P2-4 (62)P2-43-1 (96)PW-061 (80)PW-061R-2 (86)PW-141 (85) P2-23-6 (83)PW-112 (84)SP1999-65 (99)P2-84 (00) P2-35-3 (03)P2-60 (00) P2-21 (74) P2-8-3 (69) J-2 2 - 2 J-9 I-7-1 (69)J-87 (03) P2-23-3 (79)J-6-2 (87)P2-50 (00)P2-53-3 (94)P1-38-4 (97)P2-47-1 (98)J-77 (09) P2-5 (63)P2-5R-1 (71)P2-53 (1994)P1-38-4 (97)P2-8-3 (69)J-16 (89)P2-42-1 (94)P2-43-1 (96)J-5-1 (00) *HWPBA *HWPB B DAFT D DAFT C DAFT B DAFT A DIGESTER A GAS FLARES DIGESTER B DIGESTER G DIGESTER F DIGESTER C DIGESTER D DIGESTER I DIGESTER E DIGESTER H DIGESTER N DIGESTER K DIGESTER J DIGESTER T DIGESTER O DIGESTER M DIGESTER L DIGESTER S DIGESTER R DIGESTER Q DIGESTER P HEADWORKSSTANDBY *PB RADIO TOWER PARKING LOT A MAIN ENTRANCE CART BUILDING SURGE TOWER #2 SURGE TOWER #1 *JB-1 OXYGEN FACILITY EMERGENCYPOWER P.D.F. BUILDING AERATION BASINSA-H BOILER BUILDING (PENN) GAS COMPRESSORBUILDING POWER BUILDING B POWER BUILDING C POLYMER FACILITY POWER BUILDING D PEROXIDE FACILITY 1 GASSTORAGESPHERE PEROXIDE FACILITY 2 PEROXIDE FACILITY 3 PRIMARY CLARIFIER F PRIMARY CLARIFIER G PRIMARY CLARIFIER A-C PRIMARY CLARIFIER D PRIMARY CLARIFIER E DEWATERING BUILDING PRIMARY CLARIFIER L PRIMARY CLARIFIER I PRIMARY CLARIFIER K PRIMARY CLARIFIER M PRIMARY CLARIFIER O PRIMARY CLARIFIER N PRIMARY CLARIFIER P PRIMARY CLARIFIER H PRIMARY CLARIFIER J PRIMARY CLARIFIER Q SECONDARY CLARIFIERSA-L 12 KV DISTRIBUTION B 12K V DISTRIBUTION A MAINTENANCE BUILDING 12 KV DISTR I B U T I O N C *MAC CITY WATER PUMP STATION *RAS PUMP STATION (EAST) FERRIC CHLORIDE STORAGE *RAS PUMP STATION (WEST) DAFT A, B & C GALLERY SOLIDSSTORAGEFACILITY STORM WATER PUMP STATION SCRUBBERCOMPLEX(SOUTH)*DS-A PLANT WATER PUMP STATION DAFT D GALLERY & *WSSPS *DS-C SCRUBERCOMPLEX (NORTH) DIGESTERGAS STORAGETANK DIGESTERSR & SPUMP ROOM EFFLUENT JUNCTION STRUCTURE *GAC DIGESTERSP & QPUMP ROOM *PEPS SECONDARY CLARIFIER EXPANSION FINAL EFFLUENTSAMPLING STATION CONSTRUCTION MANAGEMENT COMPLEX PRIMARYINFLUENTMETERINGSTRUCTURE CENTRAL POWER GENERATION BUILDING OCEAN OUTFALL BOOSTER PUMP STATION OPERATIONS/CONTROL CENTER BUILDING PRIMARY CLARIFIERSD & E PUMP ROOM HEADWORKSCONSTRUCTIONTRAILERS WAREHOUSE PUMPSTATION C TRICKLINGFILTERCLARIFIER F TRICKLINGFILTER CLARIFIER B TR I C K L I N G FIL T E R C L A R I F I E R PU M P S T A T I O N PRIMARY POWERBUILDING A INFLUENTMETERINGSTRUCTURE DIVERSIONSTRUCTURE BAR SCREEN FACILITY PRIMARYTREATMENT FERRICCHLORIDE FACILITY GRITHANDLINGBUILDING GRIT BASINS & PRIMARY SPLITTER DISTRIBUTION CENTER H HEADWORKSODOR CONTROLFACILITY SCREENINGSLOADINGBUILDING INFLUENTPUMP STATION&DISCHARGECHANNEL SCREENINGS WASHINGBUILDING PUMP STATION A PUMP STATION B TRUNKLINE ODORCONTROL FACILITY TRICKLING FILTERCLARIFIER D TRICKLING FILTER CLARIFIER C TRICKLING FILTER CLARIFIER A DISTRIBUTION CENTER J SL U D G E R E A E R A T I O N S O L I D S C O N T A C T R E A C T O R S TRICKLING FILTER CLARIFIER E TRICKLING FILTER CLARIFIER D TRICKLING FILTER B TRICKLING FILTER C TRICKLING FILTER CLARIFIER PUMP STATION TRICKLING FILTER A *WSSPS-C CL TRUCK LOADING *IDB-2 *IDB-3 *IDB-1 *IDB-4C *IDB-48 *PEDS *JB-C *JB-A *JB-D *JB-E *JB-F *JB-A *JB-B *IDB-4A *DS-B *JB-C *PIJB-2 *PIJB-C *PIJB-B1 *PIJB-A3 *PIJB-A1 *PIJB-A 2 *SEJB *JB-8 *PWDB NATURAL GASMETERINGSTATION BLEACH STATION 12 KV DISTRIBUTIONCENTER D *EPSAELECTRICALBUILDING *ESPA-JB *EPSAPUMPSTATION METER TESTFACILITY *PWBPS POLYMERFACILITY PRIMARY CLARIFIERSA, B, AND C SLUDGE PUMP ROOM SBFELECTRICALBUILDING SCUMFACILITY SLUDGE BENDINGFACILITY SLUDGE PUMP ROOMPRIMARY CLARIFIERS A-C STANDBY POWERFACILITY DIGESTERS A & BPUMP ROOM DIGESTERS C & D PUMP ROOM DIGESTER I, J & K PUMP ROOM DIGESTERS L & MPUMP ROOM DIGESTERSN & OPUMP ROOM DIGESTERS E & HPUMP ROOM DIGESTERSF & GPUMP ROOM PRIMARYCLARIFIERSP & Q PUMP ROOM PRIMARYCLARIFIERSN & OPUMP ROOM PRIMARYCLARIFIERSL & MPUMP ROOM PRIMARYCLARIFIERSJ & K PUMP ROOM PRIMARYCLARIFIERSH & I PUMP ROOM DIGESTER TPUMP ROOM OPEN SPACE B OPEN SPACE A 78 " O C E A N O U T F A L L 12 0 " O C E A N O U T F A L L *JB-3 *JB-1 *JB-2WEST *JB-2EAST *JB-4 STORM WATERPUMP STATION OILDOCK FUTURETRICKLINGFILTER D SODIUM BISULFITE FACILITY FOSTER BOOSTERPOWER BUILDING ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Sources: Esri, HERE, DeLorme, USGS, Intermap, increment P Corp., NRCAN, Esri Japan, METI, Esri China (Hong Kong), Esri (Thailand), MapmyIndia, © OpenStreetMap contributors, and the GIS User Community DIGESTERS PUMP ROOM PROJECT LIST PRIMARY CLARIFIERS PUMP ROOM PROJECT LIST DIGESTERS A AND B PUMP ROOM DIGESTERS C AND D PUMP ROOM DIGESTERS E AND H PUMP ROOM DIGESTERS F AND G PUMP ROOMI-4-2 (67)P2-2 (60)P2-17 (72)P2-5 (63)PW-108 (84)P2-4 (62)P2-(74)I-4-2 (67)PW-141 (85)I-42 (67)PW-141 (85)PW-061 (80)PW-144 (87)PW-061 (80)P2-30 (87)PW-141 (85)J-16 (89)PW-141 (85)J-16 (89)PW-061-R2 (86)P2-37 (88)PW-061R-2 (86)P2-43-1 (96)J-16 (89)J-19-2 P2-43-1 (96)P2-43-3 (96)P2-43-1 (96)P1-38-4 P2-43-3 (96)P2-39 (00)P2-43-3 (96)P2-50 (00)P2-39-1 (00)P2-39 (00)P2-39 (00)P2-91 P2-39-1 (00)P2-91 P1-38-4 P2-50 (00)P2-38-4 PW-061R-3P2-91P1-38-4 DIGESTERS I, J AND K PUMP ROOM DIGESTERS L AND M PUMP ROOM DIGESTERS N AND O PUMP ROOM DIGESTERS P AND Q PUMP ROOMP2-14 (70)P2-19 (72)P2-21 (74)P2-24-1 (82)P2-16 (71)PW-141 (85)PW-141 (85)PW-141 (85)P2-17 (72)J-16 (89)J-16 (89)PW-144 (87)PW-141 (85)P2-39 (00)P2-39 (00)J-16 (89)P2-28-1 (87)P2-56 (00)P2-56 (00)P2-39 (00)J-16 (89)P2-91 P2-42-2 P2-56 (00)P2-39 (00)P1-38-4 P2-91 P2-47-2P2-56 (00)P1-38-4 P1-38-4P2-47-2P2-91P1-38-4DIGESTERS R AND S PUMP ROOM DIGESTER T PUMP ROOMP2-24-1 (82)P2-24-1 (82)PW-141 (85)PW-108 (84)PW-144 (87)PW-141 (85)J-16 (89)PW-144 (87)J-17-2 (93)P1-38-4P2-43-1 (96)P2-39 (00)P2-56 (00)P1-38-4 PRIMARY CLARIFIERS D AND E PUMP ROOM PRIMARY CLARIFIERS F AND G PUMP ROOM PRIMARY CLARIFIERS H AND I PUMP ROOMP2-4 (62)P2-5 (63)P2-12 (67)PW-079 (81)PW-079 (81)PW-079 (81)PW-108 (84)P2-5R-2 (86)P2-31R (87)P2-29 (86)P2-37 (88)J-16 (89)P2-43-3 (96)J-16 (89)P2-43-3 (96)P2-48 (00)P2-43-3 (96)P2-48 (00)P2-50 (00)P2-48 (00)P2-50 (00)P2-85 (03)J-5-1 (00)P2-85 (03)P2-82 (08)P2-85 (03)P2-82 (08)P2-80 (11)P2-82 (08)P2-80 (11)SP-73 P2-80 (11)P2-91P2-91 J-67 P1-38-4P1-38-4 P1-38-4PRIMARY CLARIFIERS J AND K PUMP ROOM PRIMARY CLARIFIERS L AND M PUMP ROOM PRIMARY CLARIFIERS N AND O PUMP ROOMP2-16 (71)P2-19 (72)P2-25-1A (83)PW-079 (81)P2-31R (87)P2-31-4 (87)P2-31R (87)J-16 (89)J-16 (89)J-16 (89)P2-43-3 (96)P2-43-3 (96)P2-43-3 (96)P2-48 (00)P2-48 (00)P2-48 (00)P2-50 (00)P2-50 (00)P2-50 (00)P2-85 (03)P2-85 (03)P2-85 (03)P2-82 (08)P2-82 (08)P2-82 (08)P2-80 (11)P2-80 (11)P2-80 (11)P1-38-4 P1-38-4P1-38-4PRIMARY CLARIFIERS P AND Q PUMP ROOMP2-26 (85)P2-31R (87)J-16 (89)P2-43-3 (96)P2-48 (00)P2-50 (00)P2-85 (03)P2-82 (08)P2-80 (11)P1-38-4 LEGEND o Map prepared by Orange County Sanitation District.This map is intended for graphical representation only. No level of accuracy is claimed for the base mapping shown hereon andgraphics should not be used to obtain coordinate values, bearingsor distances. Portions of this derived product contain geographicalinformation copyrighted by Thomas Brothers. All Rights Reserved. DISCLAIMER Source:OCSD GIS Data, Blue Book (CIP Database), Drawing Access System, Thomas Brothers 2010, UPDATED: JANUARY 2017 Treatment Plant 2O C S D LABELS INDICATE STRUCTURE NAMERED BLUE LABELS INDICATE JUNCTION BOX NAME LABELS INDICATE TUNNEL NAMES ABBREV GOLD & BLACK GROUND WATER REPLINISHMENT SYSTEM JUNCTION BOX POWER BUILDING PRIMARY EFFLUENT DISTRIBUTION BOX PRIMARY EFFLUENT JUNCTION BOX PRIMARY EFFLUENT PUMP STATION RETURN ACTIVATED SLUDGE SECONDARY EFFLUENT JUNCTION BOX TRICKLING FILTER EFFLUENT BOX TRICKLING FILTER SECONDARY EFLUENT WASTE SIDESTREAM PUMP STATION *GWRS *JB *PB *PEDB *PEJB *PEPS *RAS *SEJB *TFEB *TFSE *WSSPS DESCRIPTION WHITE & BLACK LABELS INDICATE OCWD STRUCTURE NAME BLACK & WHITE LABELS INDICATE PROJECT NUMBER 0 100 200 300 40050Feet Job Index Map P R I M A R YP R I M A R YC L A R I F I E R NC L A R I F I E R N P R I M A R YP R I M A R YC L A R I F I E R LC L A R I F I E R L OCSD STRUCTURES OTHER STRUCTURES STRUCTURES INCLUDED IN STUDY (BUILT BEFORE 2001) STRUCTURES NOT INCLUDED IN STUDY BUT BUILT BEFORE 2001 PS15-06 TM4 Appendix C 157 Or a n g e C o u n t y Sa n i t a t i o n D i s t r i c t PS15-06 TM4 Appendix C 158 \Mtg Minutes - OCSD 10-25-17 MEETING MINUTES SUBJECT: PS15-06 Pre TM1 Workshop DATE: Wednesday, October 25, 2017 TIME: 10:00 a.m. PST LOCATION: OCSD Plant 1, Admin Building Conference Room C MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering, Doug Lanning InfraTerra – Ahmed Nisar OCSD – Don Cutler, Mike Lahlou, Jeff Mohr, Eros Yong, Martin Dix, Mike Dorman, Anh Case 1. Safety Moment 2. Meeting Objectives 3. Review of Potential Hazards 4. Data Gap Summary 5. Investigation and Evaluation Approach a. Geotechnical i. P-197, at south side of Plant 1, may have organics where they used to dig and bury organics. ii. Plant 2 was built up historically and at one time was tidal estuary. iii. P2-98 will not be doing liquefaction mitigation for B & C clarifiers. b. Structural PS15-06 TM4 Appendix C 159 PS15-06 Pre-TM1 Meeting October 25, 2017 Page 2 i. Plant 1 Aeration Basins 1-10: Missing info on timber baffles, but probably don’t need to consider them since they are easy to repair, and they may be getting changed in a future project. ii. Consider whether some of the junction boxes identified as potential additions to the scope can be grouped and evaluated as a single representative structure. iii. Headworks Power Buildings A&B being deleted because buildings don’t have a significant long-term use (perhaps storage). iv. There may be condition assessment information on the secondary clarifiers at Plant 2. c. Risk Ranking i. Approach for integration in FMP will need to be revisited once there are hard results to discuss. Seismic, which has some probability of not occurring, could wind up driving the next 5 years of projects if allowed to override all other FMP considerations. ii. Need to add “Opportunity” into the mix of ranking decisions. If we have an opportunity to do a seismic mitigation project because we are doing another project, it may guide the order. 6. Discussion and Action Items a. After seismic event, most important will be to meet the mission of protecting public health and environment. b. Potential scope modifications i. Additional geotechnical investigation ii. Additional structures to include with the study ***** Attachments • PowerPoint slides from OCSD Presentation 10-25-17 PS15-06 TM4 Appendix C 160 Orange County Sanitation District Orange County Sanitation District PRE TM1 WORKSHOP SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 PS 15-06 | OCTOBER 25, 2017 PS15-06 TM4 Appendix C 161 Orange County Sanitation District Agenda •Safety Moment •Meeting Objectives •Review of Potential Hazards •Data Gap Summary •Investigation and Evaluation Approach •Geotechnical •Structural •Risk Ranking •Discussion and Action Items 2 PS15-06 TM4 Appendix C 162 Orange County Sanitation District Safety Moment: Santa Ana Winds 3 •...RED FLAG WARNING IN EFFECT UNTIL 6 PM PDT WEDNESDAY... •....LOW HUMIDITY AND GUSTY SANTA ANA WINDS... •BE PREPARED TO TAKE PRECAUTIONS AGAINST WILDFIRES PS15-06 TM4 Appendix C 163 Orange County Sanitation District •During a Santa Ana Wind Event •Take Shelter •Immediately go inside a sturdy building •If Caught Outside or Driving •Try to find a place that will block blowing or falling debris. •Take shelter in your car •Move your car away from trees or powerlines. •Power lines that are laying on the ground may be live. Do not go near them! •Keep a distance from high profile vehicles such as trucks, buses and vehicles towing trailers. •If Dust or Smoke Present •Get indoors. Close all windows and turn off all AC units. •If driving, pull your vehicle off the pavement as far as possible, stop, turn off lights, set the emergency brake. Never stop on the traveled portion of the roadway. Safety Moment: Santa Ana Winds 4 PS15-06 TM4 Appendix C 164 Orange County Sanitation District Meeting Objectives •Preview of TM1 •Answer questions regarding approach •Facilitate review of TM1 5 PS15-06 TM4 Appendix C 165 Orange County Sanitation District TM1 Outline 6 PS15-06 TM4 Appendix C 166 Orange County Sanitation District Seismic Design Criteria: ASCE 41-13 7 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Sp e c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (s) BSE-2N (MCER) BSE-1N (2/3 MCER) BSE-2E (5% in 50 yrs) BSE-1E (20% in 50 yrs) 5% Damped Plant 1 PS15-06 TM4 Appendix C 167 Orange County Sanitation District Design Criteria vs Faults –Plant 1 8 Design Criteria (Seismic Demand) Newport Inglewood (Max Magnitude:7.5) San Joaquin Hills (Max Magnitude:7.5) San Andreas (Max Magnitude:8.5) BSE-1E (20% in 50 yr) 225 year RP PGA=0.30 g M5.8 (Median)M5.4 (Median)M8.5 (Median+1σ) BSE-2E (5% in 50 yr) 975 year RP PGA=0.47 g M7.5 (Median+0.2σ)M6.9 (Median)M8.5 (Median+2σ) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0.0 0.5 1.0 1.5 2.0 Sp e c t r a l A c c e l e r a t i o n , S a ( g ) Period, T (s) San Joaquin (M7.5) Newport Inglewood (M7.5) San Andreas (M8.5) BSE-2E (5% in 50 yrs) BSE-1E (20% in 50 yrs) 5% Damped PS15-06 TM4 Appendix C 168 Orange County Sanitation District Seismic Design Criteria: ASCE 41-13 9 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Sp e c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (s) BSE-2N (MCER) BSE-1N (2/3 MCER) BSE-2E (5% in 50 yrs) BSE-1E (20% in 50 yrs) 5% Damped Plant 2 PS15-06 TM4 Appendix C 169 Orange County Sanitation District Design Criteria vs Faults –Plant 2 10 Design Criteria (Seismic Demand) Newport Inglewood (Max Magnitude:7.5) San Joaquin Hills (Max Magnitude:7.5) San Andreas (Max Magnitude:8.5) BSE-1E (20% in 50 yr) – 225 year RP PGA=0.29 g M5.1 (Median)M5.5 (Median)M8.5 (Median+1σ) BSE-2E (5% in 50 yr) – 975 year RP PGA=0.49 g M7.5 (Median)M7.5 (Median+0.2σ)M8.5 (Median+2σ) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 0.0 0.5 1.0 1.5 2.0 Sp e c t r a l A c c e l e r a t i o n , S a ( g ) Period, T (s) San Joaquin (M7.5) Newport Inglewood (M7.5) San Andreas (M8.5) BSE-2E (5% in 50 yrs) BSE-1E (20% in 50 yrs) 5% Damped PS15-06 TM4 Appendix C 170 Orange County Sanitation District Geotechnical Investigation –Plant 1 11 •17 CPTs •Shear wave velocity measurement at 3 CPT locations. •4 mud rotary borings PS15-06 TM4 Appendix C 171 Orange County Sanitation District Geotechnical Investigation –Plant 2 12 •11 CPTs •Shear wave velocity measurement at 1 CPT locations. •2 mud rotary borings PS15-06 TM4 Appendix C 172 Orange County Sanitation District Geotechnical Investigation –Changes in Scope 13 Original Scope of Work Proposed Investigation •26 CPTs, 50ft deep •24 CPTs, 80ft deep •4 CPTs with shear wave velocity measurement, 100ft deep •4 Mud Rotary borings, 50ft deep •4 Mud Rotary borings, 100ft deep •2 Mud Rotary borings, 80ft deep Testing •Moisture Content and Density •Modified Proctor •Sieve Analysis •Percent Finer than #200 •Atterberg Limits •Triaxial •Consolidation Additional Testing for Ground Improvement Feasibility •Corrosion Potential (Plant 1&2) •Organic Content (Plant 1) PS15-06 TM4 Appendix C 173 Orange County Sanitation District Fault Rupture–Plant 2 14 Source: Google EarthPS15-06 TM4 Appendix C 174 Orange County Sanitation District Fault Rupture–Plant 2 15 Source: Ninyo & Moore, 2010 JUNE 2017 DRAFT P2-98/ J-117 FAULT ZONEs PS15-06 TM4 Appendix C 175 Orange County Sanitation District Geotechnical Evaluation Elements 16 •Site cross-sections and individual structure soil profiles •Site models for liquefaction settlement, lateral spread, and fault rupture based on empirical tools •Assess impact of existing infrastructure (e.g. piles/ground improvement) on lateral spread and fault rupture •Develop ASCE 41-13 seismic response spectra •For Tier 3 analyses develop: –Ground motions –Axial and lateral pile capacities –Shallow foundation lateral resistance –Earth pressures on buried structures –Soil Springs •Develop mitigation measures PS15-06 TM4 Appendix C 176 Orange County Sanitation District Geotechnical Mitigation 17 Jet Grouting alongside Clarifiers at WWTP Photo: Hayward Baker •Solutions for Existing Structures •Compensation Grouting •Permeation Grouting •Piles •Jet Grouting •Lateral Spread Mitigation •Secant Pile Wall •Soil Mix Buttress •Other Technologies •Vibro Compaction •Stone Columns •New Technological Advancements •MICP (Cementation) •MIDP (Desaturation)PS15-06 TM4 Appendix C 177 Orange County Sanitation District Geotechnical Mitigation 18 Chemical Grouting Under Roadway Photo: Hayward Baker •Solutions for Existing Structures •Compensation Grouting •Permeation Grouting •Piles •Jet Grouting •Lateral Spread Mitigation •Secant Pile Wall •Soil Mix Buttress •Other Technologies •Vibro Compaction •Stone Columns •New Technological Advancements •MICP (Cementation) •MIDP (Desaturation)PS15-06 TM4 Appendix C 178 Orange County Sanitation District Geotechnical Mitigation 19 •Solutions for Existing Structures •Permeation Grouting PS15-06 TM4 Appendix C 179 Orange County Sanitation District Structural Data Gaps 20 –Material Properties •Use ASCE 41-13 default properties (based on YOC) •Assess during Task 3 if testing is viable –Piles / Post-tensioned Anchors •As needed, search OCSD library for shop drawings and test reports •Otherwise, assume least desirable attributes –Equipment weight supported from structure •As needed, search OCSD library •Otherwise, assume weight –Operating information PS15-06 TM4 Appendix C 180 Orange County Sanitation District Structural Data Gaps (cont’d) 21 –Condition Assessments •Assume a condition consistent with similar structures/age –Drawings & Shop Drawings PS15-06 TM4 Appendix C 181 Orange County Sanitation District Plant 1 –Structural Data Gaps 22 = LEVEL 2 DATA GAPS PS15-06 TM4 Appendix C 182 Orange County Sanitation District Plant 1 –Structural Data Gaps 23 PS15-06 TM4 Appendix C 183 Orange County Sanitation District Review Structure List Plant 2 24 = LEVEL 2 DATA GAPSPS15-06 TM4 Appendix C 184 Orange County Sanitation District Plant 2 –Structural Data Gaps 25 PS15-06 TM4 Appendix C 185 Orange County Sanitation District Structural Seismic Evaluation 26 •Evaluation Criteria •Data Collection •Site Visits •Identify Potential Failure Modes •Perform Analyses •Identify Vulnerabilities •Develop Mitigation Measures PS15-06 TM4 Appendix C 186 Orange County Sanitation District Structural Seismic Evaluation –Criteria 27 Buildings PS15-06 TM4 Appendix C 187 Orange County Sanitation District Structural Seismic Evaluation –Criteria 28 Water-bearing Structures & Gas Holders PS15-06 TM4 Appendix C 188 Orange County Sanitation District Structural Classifications 29 Plant Building Structures Plant 1 Waste Sludge Thickeners (DAFT) Pump Room Blower Building (at Activated Sludge 1) and PEPS Plant Water Pump Station and Power Building 6 City Water Pump Station Power Building 2 Power Building 4 Power Building 5 Control Center 12 kV Service Center Central Power Generation Building Plant 2 DAFT A, B & C Gallery DAFT D Gallery & WSSPS RAS Pump Station (East) and RAS Pump Station (West) PEPS & MAC Operations/Control Center Building 12 kV Service Center Power Buildings B Power Buildings C Power Buildings D City Water Pump Station 12 kV Distribution Center B 12 kV Distribution Center D Headworks Power Buildings A & B Headworks Standby Power Building Central Power Generation Building Class I Structures – • Essential to the maintenance of wastewater flow and treatment. •Loss of use would be a major impact ability to operate. • Significant damage could result in sewage backup and/or environmental and public health hazards. Damage Control of Class I Structures •No permanent drift is allowed. •Structures substantially retain original strength and stiffness. •Continued occupancy and operationlikely. PS15-06 TM4 Appendix C 189 Orange County Sanitation District Structural Classifications 30 Plant Non-Building Structures Plant 1 Aeration Basins 1 –10 Secondary Clarifiers 1 –26 Digester 5 and Corresponding Pump Room Digester 6 Digester 7 and Corresponding Pump Room Digester 8 Digesters 9-10 and Corresponding Pump Room Digesters 11-16 and Corresponding Pump Rooms Gas Holder Effluent Junction Box Solids Storage Facility Plant 2 Aeration Basins A – H Digester Gas Storage Tank Secondary Clarifiers A - L DAFTs A –C DAFT D Surge Tower No. 1 Surge Towers No. 2 Effluent Junction Structure Truck Loading Class I Structures – •Essential to the maintenance of wastewater flow and treatment. •Loss of use would be a major impact ability to operate. • Significant damage could result in sewage backup and/or environmental and public health hazards. Damage Control of Class I Structures •No permanent drift is allowed. •Structures substantially retain original strength and stiffness. •Continued occupancy and operationlikely. PS15-06 TM4 Appendix C 190 Orange County Sanitation District Structural Classifications 31 Class II Structures •Not directly necessary to preserve wastewater flow through the system. •Loss of use would not result in immediate wastewater backup. •Repair or replacement would be required, but need not be immediate. •Loss of life potential is low. Damage Control of Class II Structures: •Some residual strength and stiffness are allowed. • Gravity load bearing elements function. •Any out-of-plane failure of walls is not allowed. •Continued occupancy and operation might not be likely before repair. Plant Building Structures Plant 1 Chiller Building Warehouse Shop Building A Shop Building B and Building 3 Buildings 5, 6 Auto Shop Plant 2 Maintenance Building Boiler Building PS15-06 TM4 Appendix C 191 Orange County Sanitation District Structural Classifications 32 Class II Structures •Not directly necessary to preserve wastewater flow through the system. •Loss of use would not result in immediate wastewater backup. •Repair or replacement would be required,but need not be immediate. •Loss of life potential is low. Damage Control of Class II Structures: •Some residual strength and stiffness are allowed. • Gravity load bearing elements function. •Any out-of-plane failure of walls is not allowed. •Continued occupancy and operation might not be likely before repair. Plant Building Structures Plant 1 Chiller Building Warehouse Shop Building A Shop Building B and Building 3 Buildings 5, 6 Auto Shop Plant 2 Maintenance Building Boiler Building PS15-06 TM4 Appendix C 192 Orange County Sanitation District Potential Additions/Deletions 33 •Potential Additions •Plant 1: PEDB2, SEJB 1-7 •Plant 2: OOBS, JB1, JBA, JBC, SEJB junction boxes •Potential Deletions •Headworks Power Buildings A&B PS15-06 TM4 Appendix C 193 Orange County Sanitation District Structural Seismic Evaluation –Criteria 34 Performance Levels -Buildings Collapse Prevention (S-5)Life Safety (S-3)Immediate Occupancy (S-1) PS15-06 TM4 Appendix C 194 Orange County Sanitation District Structural Seismic Evaluation –Criteria 35 Performance Levels –Water-bearing Structures Collapse Prevention (S-5)Life Safety (S-3)Immediate Occupancy (S-1) Minor cracking w/ minor leaking. No permanent deformation. Facilities continue to operate w/ minimal shutdown time for repairs. PS15-06 TM4 Appendix C 195 Orange County Sanitation District Structure Type Standard Buildings ASCE 41-13 Water-bearing ACI 350 / ACI 350.3 Gas Holders API 650 Structural Seismic Evaluation –Criteria 36 PS15-06 TM4 Appendix C 196 Orange County Sanitation District Structural Seismic Evaluation –Site Visits 37 •Verify structure generally corresponds with reviewed information. •Estimate dead loads of permanent equipment and piping •Assess conditions using checklists PS15-06 TM4 Appendix C 197 Orange County Sanitation District Structural Seismic Evaluation –Analyses 38 3-Tiered Approach –Screening Phase (All Structures) •Tier 1 Checklists for Buildings per ASCE 41-13 •Data Forms for Non-Buildings Building Structures Liquid Containing Structures Data Forms ASCE 41-13 Tier 1 PS15-06 TM4 Appendix C 198 Orange County Sanitation District Structural Seismic Evaluation –Checklists 39 Buildings –ASCE 41-13 Tier 1 Checklist PS15-06 TM4 Appendix C 199 Orange County Sanitation District Structural Seismic Evaluation –Analyses 40 3-Tiered Approach –Deficiency-based Evaluation Phase •Tier 2 for Buildings per ASCE 41-13 –Tier 1 deficiencies –Potential Failure Modes •Evaluation of potential failure modes per ACI 350/350.3 for non-buildings Building Structures ASCE 41-13 Tier 1 Ground Def. OK? Yes Perform. OK? No ASCE 41-13 Tier 2 Perform. OK? Liquid Containing Structures ACI 350.3 Analysis Ground Def. OK? Perform. OK? YesData Forms PS15-06 TM4 Appendix C 200 Orange County Sanitation District Structural Seismic Evaluation –Analyses 41 3-Tiered Approach –Systematic Evaluation Phase •Tier 3 for Buildings per ASCE 41-13 •Modeling of entire structure or substantial portion –When? •Where require to evaluate response to ground deformation (in spirit of ASCE 41-13) PS15-06 TM4 Appendix C 201 Orange County Sanitation District Structural Seismic Evaluation –Ground Deformation Analyses 42 Start with 1 to 2 Trial Tier 3 to Calibrate Response Estimate Upper Bound Response Estimate Lower Bound Response Informs if Tier 3 is required for similar structures PS15-06 TM4 Appendix C 202 Orange County Sanitation District Structural Seismic Evaluation –Analyses 43 What does a Tier 3 analysis involve? –Account for response of the entire system –Usually a 3D mathematical model (finite-element model most often is used) –Modeling of foundation support PS15-06 TM4 Appendix C 203 Orange County Sanitation District Structural Seismic Evaluation –Plant 1 Analyses Forecast 44 X PS15-06 TM4 Appendix C 204 Orange County Sanitation District Structural Seismic Evaluation –Plant 2 Analyses Forecast 45 X PS15-06 TM4 Appendix C 205 Orange County Sanitation District Structural Seismic Evaluation –Develop Mitigation Measures 46 •Revised operation •General strengthening •Component retrofit •Reduction of mass •Coordinated geo/structural measures •Replacement PS15-06 TM4 Appendix C 206 Orange County Sanitation District •Ability to meet level of service •Remaining life of the facility after seismic mitigation •Life cycle cost for mitigation vs. replacement •Ability to take facility out of service for seismic mitigation Risk Approach Basis for Mitigation vs. Replacement 47 PS15-06 TM4 Appendix C 207 Orange County Sanitation District Risk Approach Risk-Based Prioritization Approach 48 Consequence of Failure (CoF) High Low High Risk Low Risk HighLow Likelihood of Failure (LoF) PS15-06 TM4 Appendix C 208 Orange County Sanitation District •RoSF = LoSF x CoF •RoSF –Risk of Seismic Failure •LoSF –Likelihood of Seismic Failure •CoF –Consequence of Failure •LoSF is likelihood that structure cannot meet performance requirements after the design seismic event •Rated from 1 to 5, with 5 being most likely •Performance requirements either Class I or Class II as established at P1 and P2 workshops –to be confirmed following evaluation •CoF evaluated same as Facility Master Plan •Sorted from highest RoSF to lowest Risk Approach Basis for Seismic Projects Risk Ranking 49 PS15-06 TM4 Appendix C 209 Orange County Sanitation District •Regulatory, IF = 100% •Stakeholder Commitments, IF = 75% •Financial, IF = 50% •Public Impacts, IF = 33% Risk Approach CoF and Importance Factors (per Facility Master Plan) 50 PS15-06 TM4 Appendix C 210 Orange County Sanitation District •RoSF = LoSF x CoF •RoSF –Risk of Seismic Failure •LoSF –Likelihood of Seismic Failure •CoF –Consequence of Failure •LoSF = 4 (out of 5) that Structure XYZ cannot meet performance requirements after the design seismic event •Maximum CoF = 3 (out of 5) for Financial impacts •Financial IF = 50%, so weighted CoF = 3 x 50% = 1.5 •RoSF = 4 x 1.5 = 6 Risk Approach Example for Seismic Project Risk Ranking 51 PS15-06 TM4 Appendix C 211 Orange County Sanitation District Risk Approach Facility Master Plan (FMP) Framework 52 Failure Modes for LoF 1.Condition 2.Capacity 3.Redundancy 4.Regulations 5.Initiative 6.Seismic 7.Health and Safety PS15-06 TM4 Appendix C 212 Orange County Sanitation District Risk Approach Integration with FMP 53 PS15-06 TM4 Appendix C 213 Orange County Sanitation District •Effectiveness of seismic mitigation •Constructability of seismic mitigation •Construction cost for seismic mitigation •Post-event repair cost, duration, and CoSE vs. mitigation Risk Approach Potential Additional Considerations 54 LoF can be modified in response to these considerations on a case-by-case basis PS15-06 TM4 Appendix C 214 Orange County Sanitation District Action Items/Summary 55 •Incorporate OCSD input into TM1 •TM1 Draft –10/31/17 PS15-06 TM4 Appendix C 215 Orange County Sanitation District Thank You! 56 PS15-06 TM4 Appendix C 216 \Mtg Minutes - OCSD 8-15-18 w Jacobs edits MEETING MINUTES SUBJECT: PS15-06 Project Progress Update DATE: Wednesday, August 15, 2018 TIME: 1:00 p.m. PST LOCATION: OCSD Administration Building, Conference Room A MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt, Jeff Fijalka Carollo – James Doering, Doug Lanning InfraTerra – Ahmed Nisar OCSD – Don Cutler, Mike Lahlou, Eros Yong, Jacob Dalgoff, Kathy Millea, Dean Fisher, Jeff Mohr, Mike Dorman, Martin Dix Jacobs (via phone) – Elias Mageaes, Kirk Warnock, Jeong Yang 1. Introduction/Safety Moment C. Conkle presented safety moment. Topic: Downed Powerlines – always assumed energized, avoid contact, call 911. 2. Review Project Objectives Conkle described the objectives of the meeting as outlined on the attached slides. 3. Progress Update Conkle described project progress to date. TM1 (background) and TM2 (geotechnical investigation and report), complete Task 3 Structural evaluations and mitigations, in progress Task 4 Planning and risk ranking, upcoming – March 2019 completion PS15-06 TM4 Appendix C 217 PS15-06 Project Progress Update August 15, 2018 Page 2 4. Geotechnical Site Conditions/Risks Conkle provided overview with emphasis on liquefaction and lateral spread. Chris Hunt described the geotechnical investigation and seismic design criteria. Explanation of the development process for an analysis groundwater level. Summarized ground deformations. Showed example structure-specific soil profile and settlement and lateral spread distribution profiles. Explained deformation summary handouts (attached). Explained background regarding liquefaction hazard at Plant 1. Based on existing available information regarding fault rupture hazard deformations due to fault rupture pose a smaller risk to existing structures at Plant 2 than liquefaction and lateral spread hazards and are not being considered explicitly in Task 3. Questions/Discussion items during this section of the meeting included: Mageaes: How was PGA developed? o Nisar/Hunt: Following ASCE 41-13 and ASCE 7-10 requirements, using USGS tables Yong: Was a trend in water level over time observed? o Hunt: Yes at Plant 1 some trends were observed in OCWD well data but analysis water level was selected to envelope these trends. Dorman: At what depth does liquefaction occur? o Hunt: Liquefaction can occur at depth below the water table where soils are loose enough. Warnock: Shouldn’t the Factor of Safety on Slide 24 be represented as points instead of lines? o Hunt: Each line represents nearly continuous information from a single CPT. Tip resistance can change nearly every cm, and thus Factor of Safety will change. o Cutler: This matter can be addressed later in the month at separate meeting. Mohr: (Referring to the settlement/lateral spread figure) Is there about 9 inches of settlement? o Hunt: Settlement varies from about 3.5 to 10 inches. The black line is the recommended best estimate of settlement which was used in the structural evaluations. The red line represents a reasonable upper bound estimate. There are some outliers. Warnock: What does “best” mean (regarding “best estimate”)? o Hunt: Best geotechnical judgement. Mohr: Do these deformation values assume no influence from structure? o Hunt: Yes, these are free field estimates. Mageaes: Are we confident in the data used to assign the water level at Plant 1? PS15-06 TM4 Appendix C 218 PS15-06 Project Progress Update August 15, 2018 Page 3 o Hunt/Conkle: Yes. Multiple monitoring wells are present near Plant 1. Also reviewed historical onsite well data and boring data. 5. Structural Evaluations and Mitigations For analysis purposes, structures were grouped according to structural/functional similarities. Per Doering, ground shaking is the primary structural hazard for some structures. Digesters Nisar provided an overview of the Plant 1 digester evaluations. Greater lateral deformation is estimated along row of digesters nearest river. Digesters are founded on piles. Deformation information and ground shaking information provided by the geotechnical team was used as inputs to model how the digesters response. These structures have sufficient reinforcement, however lateral displacement will exceed capacities of piles. Limiting lateral displacement to approximately 24 inches or less will require geotechnical mitigation. Questions/Discussion items during this section of the meeting included: Mohr: If the digesters move, will piles move with it? o Nisar: Yes, to an extent the pile will move with the ground. Dorman: Lateral displacement is shown as range, which value do you use in analysis? The average? o Nisar: The calculated displacement is approximately the average of the range of values. Model includes all piles and load is applied to each pile. o Doering: The nature of the foundation system helps distribute loads and average the displacement. Mohr: With 24 inches of movement, there is no collapse of the tank, but the tank may not be useable? o Nisar: Correct, piping would possibly need to be restored. o Conkle: At 24 inches, the structure/foundation remains intact. o Mohr: It is just not functional? o Nisar/Conkle: Correct. Cutler pointed out that on slide 42, the expansion joints on the piping in the picture from Kobe appear to have performed well during an earthquake. Mageaes: Were you able to determine the longitudinal pre-stressing in the piles from the as-built drawings? o Nisar: Yes,. o Conkle: This topic can be held for the technical meeting. PS15-06 TM4 Appendix C 219 PS15-06 Project Progress Update August 15, 2018 Page 4 Hunt discussed possible options to address lateral spread at each site. One option is to improve a zone of soil between the structures and the river/marsh. A second option would be to construct a deep structural wall in this same zone. Presented slides on each option. Structural wall could be installed in independent segments to address particular vulnerabilities to lateral spreading identified. Questions/Discussion items during this section of the meeting included: Yong: Could these options address lateral spread for entire plant? o Hunt: Yes, the walls could be designed to achieve specified performance level to address requirements of various structures. o Nisar: Currently looking structure-by-structure, but there could be a plant-wide fix that lowers lateral spread risk. o Conkle: A wall could be designed to address a specific set of structures. Must still consider settlement independently. o Nisar: In some cases settlements will already be mitigated by piles. Secondary Clarifiers Nisar explained evaluations/challenges related to the secondary clarifiers: large structures, many joints, need to keep scrapers operable. Large lateral displacements estimated along marsh. Presented finite element model results. Significant separation at expansion joints due to lateral spread and settlement (greater than 6 inches). Showed examples of structural deformations from Kobe earthquake. Currently considering if structures could be tied together across expansion joints. Options: tie slab segments together, secant pile wall, ground improvement below structure. Questions/Discussion items during this section of the meeting included: Hunt: There is limited room to install soil improvement zone around these structures. Must work below structure to address settlement. If possible, this would reduce lateral spread too. Mohr: Tying structure together will prevent pull apart and shear, or both? o Nisar: Both. o Mohr: Wouldn’t this induce stress under operating loads? o Nisar: Yes, design must consider this. Mohr: Are the clarifiers not on piles? o Nisar: No for Plant 2. o Fisher: There are tie-down anchors. o Nisar: Yes, for buoyancy. PS15-06 TM4 Appendix C 220 PS15-06 Project Progress Update August 15, 2018 Page 5 Yong: Would a model need to be developed to assess how structural mitigations may impact the structure? o Nisar: Yes this would require analysis. Mohr: From a planning perspective, we need to make sure we aren’t spending too much effort on evaluation of clarifiers that have limited remaining useful life. o Conkle: We will develop alternatives with costs to allow for discussion. Some alternatives may be kicked out during Task 4 because cost may outweigh the benefit. o Mohr: We aren’t going too far into that analysis? o Nisar: Correct, we are not spending significant analytical effort towards design; however, we need to look at structural options so that OCSD has a basis to make appropriate decisions. o NOTE: To elaborate and clarify Conkle and Nisar responses, the evaluations performed as part of Tasks 3 and 4 will be performed at a level of detail appropriate to establish likely planning-level costs. Hunt presented the concept that walls could be constructed at Plant 2 along the full length of the river and marsh. These would not need to be continuous. Questions/Discussion items during this section of the meeting included: Mohr: Could the wall be constructed in certain areas only? o Hunt: Yes. Yong: This study is not looking at some structures because of their construction dates, however, what do these results mean for those structures? o Conkle: The subject structures were identified as higher risk. There may be potential to extend some of these concepts, but this study does not include evaluations of these newer structures. Mohr: Not sure if these deformations were a consideration back when other structures were constructed. Lateral spread was not often discussed. o Yong: OCSD can look at P2-90 geotechnical reports. o Millea: That was re-designed in 2005. o Yong: P2-66, was lateral spread considered? o Lanning and Doering: Not to their recollection o Hunt: Structures located 500-700 ft back from the river are typically outside the lateral spread zone. Mohr: For a new structure along marsh or river, could it be designed with lateral piles? PS15-06 TM4 Appendix C 221 PS15-06 Project Progress Update August 15, 2018 Page 6 o Hunt: You could improve the ground below and around, construct a structural wall in front, or design heavily reinforced piles. o Nisar: Soil mixing for ground improvement could work if completed in advance of the construction of the structure. o Mohr: Possibly P2-90 was designed with lateral spread taken into consideration? o Millea: Does not believe lateral spread was considered. Dalgoff: Does lateral displacement only occur towards the river? Doesn’t lateral displacement need to be addressed in all directions? o Hunt: If the river was not there, there would be nowhere for lateral spread to occur. A free face or a sloping ground surface is required for lateral spread to occur. Cases have shown that lateral spread can occur below the depth of the free face. In our analysis, we looked for the lowest continuous layer that liquefies and assumed that spread doesn’t go below this layer. This is not the case for settlement, it propagates down. Lateral spread has to move toward the river and it can go below river bottom. Yong: For new construction, could piles be designed deep enough and strong enough to resist these deformations? o Hunt/Nisar: Yes, potentially, depending on the structure, its configuration, and the applied loads. o Hunt: Or you could improve the ground. Surge Towers Ahmed described the findings related to the surge tower. May experience some settlement and tilt. Evaluation did not look at impacts of movement to the connecting pipe below the tower. Questions/Discussion items during this section of the meeting included: Mohr: Since the pipe is parallel to the river, it may move together toward the river. Nisar: Possibly, but movement will be influenced by connections. Yong: The surge tower is two different materials. Was this evaluated? o Nisar: Yes and for seismic conditions it was not modeled as filled with water. o Conkle: An evaluation water level was selected for each structure. Gas Holders Nisar explained that the gas holder will likely perform well. Anchor straps at the base of similar tanks have failed in the past, however, these tanks hold gas, not water. May consider improving straps. PS15-06 TM4 Appendix C 222 PS15-06 Project Progress Update August 15, 2018 Page 7 Aeration Basins Doering discussed the evaluations for the aeration basins and other structures. There are many issues related to shaking alone. Aeration basins will behave similar to secondary clarifiers. Decks may fall if walls move apart. Could structurally support the deck to allow for greater displacement. Peps/MAC at Plant 2 Peps/MAC at Plant 2, large structure with basement. Contains vertical irregularities. Shear walls that don’t fully transfer load to foundation system. Leads to excessive vertical forces, may need to fill in some windows, will reduce stress on end shear walls. Plant 1 City Water Pump Station Key vulnerability: slab on-grade not tied to wall or footing in some cases. Footings may move independent of walls. Steel angle connections are one potential retrofit. Control Center 2-story steel frame with basement on piles. One of a few steel frame (moment resisting) structures at these sites. Designed to dissipate energy through joints in frame. May need to add beams to convert to a braced structure. Constructed from moment frames with wide flange columns, in half of structure beams are rotated 90 degrees (along week axis). May experience significant torsion/drift due to this. Non-structural damage will result. Columns are anchor bolted only to basement floor. Questions/Discussion items during this section of the meeting included: Mohr: When was this designed? o Doering: 1995-96, early after Northridge, design of moment frames was still not great at that time. Structure has some vulnerabilities in “pre-Northridge” joints. 6. Next Steps Conkle: Need for additional meetings with OCSD to discuss and develop alternatives. Produce and deliver TM3. Develop final list of projects and rank them (TM4). 7. Questions/Discussion Mohr: Have we figured out methodology/criteria to determine which projects are higher priority than others? PS15-06 TM4 Appendix C 223 PS15-06 Project Progress Update August 15, 2018 Page 8 o Cutler: Part of TM4 will use a methodology that has been established. o Lanning: This project will prioritize seismic projects relative to only seismic projects. It will also set up a framework to compare to other non-seismic projects. PS15-06 will set up the framework but will not carry it through to the FMP. o Millea: (Planning) will likely review and determine what we want to do, and will have to accept risk. Might not be many stand-alone seismic projects. o Mohr: TM4 will shift from consultant technical work to OCSD using philosophical method to prioritize and rank. o Cutler: That is part of the reason that this is a good starting point to get stakeholders engaged. Will continue with more discussions with stakeholder to work through this. o Mohr: Will receive skepticism from the board and the public about estimated seismic hazards. o Lanning: Is there something we need to do to help explain that? o Mohr: Must be able to explain the priorities such that public will understand it. That is the challenge of this assignment. It will be tough for people to take seriously. Dorman: Control center damage is result of shaking, not ground deformation? o Doering: Yes. Mohr: What happens to OOBS? o Doering: Still working on it. It needs finite element evaluation because there are structures next to each other. Deformations could lead them into or away from each other. Both are on thick slabs which bring floors lower than they otherwise would be. Dorman: How about 12 KV service center at P2? o Doering: It has an unusual 7.5” corrugated steel deck. Has little strength in one direction. Still analyzing this. It could be supplemented with steel beams below. Can also fill windows to increase capacity. Mohr: Could possibly do many seismic retrofits as part of one project. Millea: Will any geotechnical guidance/recommendations for future new projects be developed as part of this study? Or just follow current codes? o Cutler: This study is imposing different requirements for existing structure than current “new construction” codes. o Mohr: What is being done for lateral spread at P2-98? o Dalgoff: Soil mixed columns, hundreds of them. o Conkle: While not currently part of this project, may be beneficial to develop best practice as team to recommend moving forward for new construction. o Dorman: Good idea. PS15-06 TM4 Appendix C 224 PS15-06 Project Progress Update August 15, 2018 Page 9 o Mageaes: The Plant 1 and Plant 2 site-specific data for seismicity and seismic design parameters, along with proposed analysis groundwater levels and historical high groundwater levels that were all developed as part of Task 2 of this study, could be used by OCSD on future designs as reference data. These values could be compared to what the future project Geotech and Engineer recommend and use in their design. In case of significant data variance, a justification or a second look would be required. o Conkle: Groundwater level and lateral spread are based on seismic hazard levels being assessed as part of this study, but these may be different than what is used on other new building projects. o Cutler: We are working to bring seismic design standards to current codes. We should be looking forward, not behind. o Millea: Should make sure projects in the works now are using current guidelines. o Dix: (I) hoped this project would update design guidelines. o Mohr: Is that part of this project? Would be a good idea. o Conkle/Cutler: That is not currently part of this project but we will discuss. o Jacobs: ASCE7-10 will be replaced by ASCE7-15 and will require tsunami design. This may cause concerns/pushback from the community. o Dorman: For design considerations, should make sure others have access to the data gathered from this study. o Doering: Most structures have been the subject of several projects. Should have way to tie that together. o Lahlou: We are building a database of CPTs which will be on OCSD SharePoint. o Hunt: The handouts provided show structures specific to the structures under study. While it may seem useful to show zones, this data is specific to these structures, water levels, etc. Need to make sure that is information is presented in appropriate context and not misused. o Conkle: A guidance document which is developed out of his study could provide guidance to designers and OCSD as building official. Action Items: Geosyntec to prepare meeting minutes. Mohr: study conclusions should be presented to the Board. Before budgeting would be ideal. o Conkle: final document is scheduled for submittal in March. PS15-06 TM4 Appendix C 225 PS15-06 Project Progress Update August 15, 2018 Page 10 o Mohr: Probably won’t be used to re-define the priorities for next year. More likely it will be used for following year. Maybe shift the priority of one or two projects. Projects typically defined in December for the following year. May inform planned projects (Ex. omit new landscape if ground improvement will later be done) Conkle: Meetings will be needed to help define TM4 process. ***** Attachments PowerPoint slides from Presentation 8-15-18 Handouts from 8-15-18 meeting PS15-06 TM4 Appendix C 226 Orange County Sanitation District Orange County Sanitation District PROJECT PROGRESS UPDATE SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 AUGUST 15, 2018 PRESENTED BY: Geosyntec Team PS15-06 TM4 Appendix C 227 Orange County Sanitation District Agenda •Introductions/Safety Moment •Review Project Objectives •Progress Update •Geotechnical Site Conditions/Risks •Structural Evaluations and Mitigations •Next Steps •Questions/Discussion 2 PS15-06 TM4 Appendix C 228 Orange County Sanitation District Safety Moment – Downed Powerlines 3 • Live or Deenergized? PS15-06 TM4 Appendix C 229 Orange County Sanitation District Safety Moment – Downed Powerlines 4 • A live and deenergized line look the same! • No sparks or movement. • May restore power to the line without warning. • The protective covering on a power line is not insulation • Keep away from any object that is in contact with a power line (including the ground!) • PS15-06 TM4 Appendix C 230 Orange County Sanitation District Safety Moment – Downed Powerlines 5 • Treat downed power lines and anything in contact with them as energized. Stay far away from any downed line. Stay back at least 33 feet away (That's about the length of a city bus.) • Call 911 (or 211) and the power company immediately. A crew with proper training and equipment will arrive as soon as possible. • Wait for the power company representative to confirm that it is safe to approach the scene. PS15-06 TM4 Appendix C 231 Orange County Sanitation District Introductions •The Geosyntec Team: •Chris Conkle •Chris Hunt •Jeff Fijalka •James Doering (Carollo) •Doug Lanning (Carollo) •Ahmed Nisar (InfraTerra) •OCSD Team 6 PS15-06 TM4 Appendix C 232 Orange County Sanitation District Meeting Objectives •“In progress” update on project •Preview of findings regarding structures •Preview of mitigation recommendations •Facilitate review of Upcoming Deliverables 7 PS15-06 TM4 Appendix C 233 Orange County Sanitation District Review Project Objectives 8 PS15-06 TM4 Appendix C 234 Orange County Sanitation District Project Objectives •Identification of critical structural vulnerabilities for project structures •Development of retrofit recommendations •Planning Level for incorporation into facility master plan. •In addition, develop high level understanding of seismic risks throughout both Plants 9 PS15-06 TM4 Appendix C 235 Orange County Sanitation District Project Objectives – Plant 1 10 PS15-06 TM4 Appendix C 236 Orange County Sanitation District Project Objectives – Plant 2 11 PS15-06 TM4 Appendix C 237 Orange County Sanitation District Progress Update 12 PS15-06 TM4 Appendix C 238 Orange County Sanitation District Progress Update 13 •Completed Tasks –TM1 – Background Development –TM2 – Geotechnical Site Investigation •In Progress –Task 3 – Combined Geotechnical and Structural Evaluations •Upcoming –Task 4 – Completion – March 2019 PS15-06 TM4 Appendix C 239 Orange County Sanitation District Geotechnical Site Conditions/Risks 14 PS15-06 TM4 Appendix C 240 Orange County Sanitation District Geotechnical Overview 15 •Site Investigation •Seismic Hazard Level •Water Level Evaluation •Idealized Soil Profiles •Liquefaction settlement and lateral spread •Consideration of Fault Rupture PS15-06 TM4 Appendix C 241 Orange County Sanitation District Liquefaction and Lateral Spreading 16 PS15-06 TM4 Appendix C 242 Orange County Sanitation District Liquefaction and Lateral Spreading 17 PS15-06 TM4 Appendix C 243 Orange County Sanitation District Liquefaction and Lateral Spreading 18 PS15-06 TM4 Appendix C 244 Orange County Sanitation District Liquefaction and Lateral Spreading 19 PS15-06 TM4 Appendix C 245 Orange County Sanitation District Geotechnical Investigations – Plant 1 20 CPT-01 BH-01 CPT-13 CPT-11 CPT-10 CPT-09 CPT-02 CPT-07 CPT-12 CPT-06 CPT-14 CPT-15 CPT-16 CPT-17 CPT-05 CPT-08 BH-02 CPT-04 BH-04 CPT-03 BH-03 CPT CPT/Boring Pair Previous CPT Previous Boring LEGEND PS15-06 TM4 Appendix C 246 Orange County Sanitation District Geotechnical Investigations – Plant 2 21 CPT-04 CPT-11 CPT-09 CPT-08 CPT-10 CPT-06 CPT-02 CPT-05 CPT-03 CPT-07 BH-02 CPT-01 BH-01 CPT CPT/Boring Pair Previous CPT Previous Boring LEGEND PS15-06 TM4 Appendix C 247 Orange County Sanitation District Seismic Design Criteria 22 •Two earthquake hazard levels for existing structures •BSE-1E Hazard Level (~immediate occupancy) •20% Probability of exceedance in 50 years / 225 year recurrence interval •BSE-2E Hazard Level (~life safety) •5% probability of exceedance in 50 years / 975 year recurrence interval •Plant 1 •BSE-1E: PGA = 0.30g •BSE-2E: PGA = 0.46g •Plant 2 •BSE-1E: PGA = 0.29g •BSE-2E: PGA = 0.48g San Andreas Fault is 48 miles NE of Plant 1 Note: New construction typically considers BSE-2N, 2,475 yr recurrence (PGA ≈0.65g) BSE-1N, 2/3rds of BSE-2N (PGA ≈ 0.43g) PS15-06 TM4 Appendix C 248 Orange County Sanitation District Analysis Water Level (16 ft-NAVD88) •Historic High Water Level (HHWL) often used for new construction •Using “Analysis Water Level (AWL)” for planning study of existing structures •Based on review of site-specific information (boring logs and limited well data) •In all cases, lower than equivalent HH level •Plant 1: +16 ft (NAVD ’88) •Plant 2: +2 ft (NAVD ’88) Groundwater Level Approach 23 Plant 1 Analysis Water Level Evaluation PS15-06 TM4 Appendix C 249 Orange County Sanitation District Idealized Soil Profile – Digester 16 24 PS15-06 TM4 Appendix C 250 Orange County Sanitation District Idealized Soil Profile – Digester 16 25 PS15-06 TM4 Appendix C 251 Orange County Sanitation District Liquefaction Displacements – Digester 16 26 Focus is on “best estimate” case, with consideration of effects of “upper estimate”. PS15-06 TM4 Appendix C 252 Orange County Sanitation District Liquefaction & Lateral Spread – Plant 1 27 1-28 to 1-32 4.5 (5) No LS Structure settlement, inches lateral spread, inches Best (Upper Estimate) At Analysis Water Level 1-8 3 (4.5) No LS 1-6 3 (5) No LS 1-27 4.5 (5.5) No LS 1-4 3.5 (5) 11-18 (13-22) 1-26 6.5 (9) 13-18 (22-31) 1-11 6 (8) 6-16 (10-26) 1-12 6 (8) 6-38 (9-56) 1-1 6.5 (8) 13-27 (22-46) 1-3 6.5 (8) 26-40 (34-53) 1-9 8.5 (11) 11-12 (14-16) 1-25 6.5 (8.5) 16-150 (50-165) 1-2 4.5 (7) 5-6 (11-15) 1-33 4.5 / 7 No LS 1-16 to 1-20 8.5 (10) 1-16 15-19 (22-29) 1-17 16-17 (24-26) 1-18 14-18 (21-28) 1-19 20-40 (33-64) 1-20 21-29 (32-45) 1-5 7.5 (9) 17-25 (28-40) 1-21A 7.5 (10) 17-35 (26-52) 1-21B 8 (10) 11-16 (17-24) 1-22 8 (10) 13-26 (19-38) 1-23 6 (7.5) 13-20 (18-29) 1-7, 1-10, 1-13 to 15, 1-24 8 (10) 1-7 9-10 (12-13) 1-10 7-8 (7-9) 1-13 9-10 (9-11) 1-14 8-9 (9-10) 1-15 8-9 (8-9) 1-24 10-11 (11-12) 2-21B 2-21A Geosyntec CPT Geosyntec Boring Previous CPT Previous Boring LEGENDFree Face ≈ 10 ft Free Face ≈ 15 ft PS15-06 TM4 Appendix C 253 Orange County Sanitation District Why Liquefaction at Plant 1? 28 •Plant 1 and 2 sit within the historic floodplain of the Santa Ana River •Historic river meanders and deposition from flooding leave behind loose sandy soils PS15-06 TM4 Appendix C 254 Orange County Sanitation District 2-27 11 (12) No LS 2-13 11.5 (13) No LS 2-11 11.5 (13) No LS 2-6 11.5 (13) No LS 2-7 11 (11) 15-16 (17-19) 2-17 7.5 (13) 12-21 (16-27) 2-29 7.5 (14) 21-92 (33-145) 2-10 5 (6) No LS 2-8 and 2-28 5 (6) No LS 2-26 7.5 (10) No LS 2-9 6 (7.5) 7-8 (10-11) 2-1 6 (9) 7-14 (15-28) 2-2 7 (9) 10-22 (20-42) 2-21 6 (9.5) 8-14 (13-24) 2-22 7.5 (9) 14-28 (26-52) 2-20 7 (10) 6-17 (7-23) 12-66 (16-77) 2-14 to 16, 2-30 13 (17) 2-14 16-17 (23-25) 2-15 18-19 (25-27) 2-16 17-19 (25-28) 2-30 17-20 (25-30) 2-24 8.5 (11) 45-65 (65-95) 2-31 8 (10) 19-21 (38-42) 6 (12) 2-12 8.5 (13.5) 16-23 (38-51) 9-10 (21-23) 2-5 8.5 (13.5) 19-28 (28-42) 15-17 (24-26) 2-4 3 (4) 1 (1) 1 (2) 2-18A 4 (5.5) 1 (2-3) 1 (2-3) 2-19 3.5 (4) 1 (1) 1 (2) 2-18A 2-18B 2-32 11 (17) 43-75 (75-130) Geosyntec CPT Geosyntec Boring Previous CPT Previous Boring LEGEND 2-18B 5.5 (7.5) 9-16 (18-31) 9-13 (18-26) 2-3 5.5 (7.5) 13-16 (18-31) 11-13 (21-25) Liquefaction & Lateral Spread – Plant 2 29 Structure settlement, inches lateral spread (river), inches lateral spread (marsh), inches Best (Upper Estimate) At Analysis Water Level PS15-06 TM4 Appendix C 255 Orange County Sanitation District Fault Rupture Hazard – Plant 2 Only 30 •Numerous faults can cause liquefaction and strong shaking at Plant 2 •Only one fault (Newport- Inglewood) can cause fault rupture •Risk to existing structures from fault rupture displacements is significantly lower than that from liquefaction-induced displacements and settlement PS15-06 TM4 Appendix C 256 Orange County Sanitation District Structural Evaluations and Mitigations 31 PS15-06 TM4 Appendix C 257 Orange County Sanitation District Structural Groups 32 Buildings – Shallow Foundations Buildings - Mat Foundation Buildings - Deep Foundations Gas Holders Surge Towers Buried Boxes Secondary Clarifiers Aeration Basins Digesters DAFTs . PS15-06 TM4 Appendix C 258 Orange County Sanitation District Digesters 33 PS15-06 TM4 Appendix C 259 Orange County Sanitation District 34 1111 1212 1313 1414 1515 1616 66 77 88 99 1010 55 35”35” 17”17” 16”16”11”11” PS15-06 TM4 Appendix C 260 Orange County Sanitation District Foundation Plan 35 Diameter = 110 ft PS15-06 TM4 Appendix C 261 Orange County Sanitation District 36 Plant 1 Digester 16 PS15-06 TM4 Appendix C 262 Orange County Sanitation District 37 PS15-06 TM4 Appendix C 263 Orange County Sanitation District 38 Digester Piles 21 inches Front Row Back Row 24 inches PS15-06 TM4 Appendix C 264 Orange County Sanitation District Earthquake Damage – 1995 Kobe, Japan 39 Concrete piles supporting digester closest to channel cracked at the top Differential settlement between pile supported digester and adjacent ground PS15-06 TM4 Appendix C 265 Orange County Sanitation District • Digesters • Piles for front row of digesters closest to the river (7- 12) are vulnerable to significant damage • Piles for back row of digesters will deform but maintain capacity • Reduction of lateral spread displacement through ground improvement will improve seismic performance of digesters Items for Discussion 40 PS15-06 TM4 Appendix C 266 Orange County Sanitation District • Ground improvement options to limit lateral spread Digesters – Lateral Spread Mitigation 41 Santa Ana RiverDigester Ground Improvement Zone PS15-06 TM4 Appendix C 267 Orange County Sanitation District • Option 1: Ground improvement to limit lateral spread • Construct ground improvement shear panels • Ground improvement methods: Auger soil mixing, cutter soil mixing, slurry wall method, jet grouting, … • Key ground improvement elements: • Large footprint (utility relocation, surface disruptions) • Must achieve high strength and/or large “replacement volume” • “Key” improvement below lateral spread zone (Digesters~ Elev. -10 feet) Lateral Spread Mitigation Concepts 42 PS15-06 TM4 Appendix C 268 Orange County Sanitation District • Option 2: Subsurface retaining wall to limit lateral spread • Design wall to resist earth pressure from lateral spread without excessive deflection – soil “in front” of wall would still move away • Wall types: secant pile wall, cutter soil mix wall, … • Key wall elements • Smaller footprint • Significant depth (~100 ft), founded below liquefaction zone • Heavily reinforced to limit deflections Lateral Spread Mitigation Concepts 43 PS15-06 TM4 Appendix C 269 Orange County Sanitation District • Secant Pile Wall Installation Digesters – Lateral Spread Mitigation 44Image Source: Hayward Baker PS15-06 TM4 Appendix C 270 Orange County Sanitation District Secondary Clarifiers 45 PS15-06 TM4 Appendix C 271 Orange County Sanitation District Secondary Clarifiers 46 Expansion Joints 44” 32” 32” 29” 10” 11” 12” 16” PS15-06 TM4 Appendix C 272 Orange County Sanitation District Secondary Clarifiers FE Model PS15-06 TM4 Appendix C 273 Orange County Sanitation District Secondary Clarifiers 48 Lateral Spread Settlement PS15-06 TM4 Appendix C 274 Orange County Sanitation District Earthquake Damage – 1995 Kobe, Japan 49 Expansion joint separation along entire bank Damage to sludge scraper chains Damage to water stops PS15-06 TM4 Appendix C 275 Orange County Sanitation District Earthquake Damage – 1995 Kobe, Japan 50 Effluent channel offset nearly 1m from lateral spread Building movement PS15-06 TM4 Appendix C 276 Orange County Sanitation District Secondary Clarifiers Structural Upgrade Option 51 W12x196 Beams Added (longitudinal direction)W12x196 Beams Added (transverse direction) PS15-06 TM4 Appendix C 277 Orange County Sanitation District • Option 1: Secant pile wall to limit lateral spread towards marsh, but not control settlement • Option 2: Ground improvement below clarifiers to limit both settlement and lateral spread • Either option would stabilize lateral spread towards marsh for structures “behind” clarifiers as well Secondary Clarifiers – Geotech Mitigation 52 PS15-06 TM4 Appendix C 278 Orange County Sanitation District • Secant Pile Wall Installation along River and Marsh Lateral Spread Mitigation – Plant 2 Concept 53 • Lateral Spread “cutoff” wall • May need to be installed outside property line • Can be locally stopped or shifted back where utilities cross • Will not mitigate settlement PS15-06 TM4 Appendix C 279 Orange County Sanitation District • Secondary Clarifiers • Large lateral spread deformation and settlement results in significant differential movement across expansion joints • Structurally connecting clarifiers across expansion joints is a potential structural retrofit • Ground improvement will reduce lateral spread but impractical to reduce settlements • Ground improvement together with structural retrofit would improve seismic performance Items for Discussion 54 PS15-06 TM4 Appendix C 280 Orange County Sanitation District Surge Tower 55 PS15-06 TM4 Appendix C 281 Orange County Sanitation District Surge Tower 2 56 65” PS15-06 TM4 Appendix C 282 Orange County Sanitation District Surge Tower 2 57 Mode shape Tilt from settlement PS15-06 TM4 Appendix C 283 Orange County Sanitation District 58 PS15-06 TM4 Appendix C 284 Orange County Sanitation District 59 PS15-06 TM4 Appendix C 285 Orange County Sanitation District • Surge Towers • Acceptable performance for ground shaking • Liquefaction-induced lateral spread will result in sliding, which will significantly damage connection with outfall pipeline • Liquefaction-induced settlement causes minor tilting Items for Discussion 60 PS15-06 TM4 Appendix C 286 Orange County Sanitation District Gas Holder 61 PS15-06 TM4 Appendix C 287 Orange County Sanitation District Gas Holder 62 PS15-06 TM4 Appendix C 288 Orange County Sanitation District Gas Holder 63 PS15-06 TM4 Appendix C 289 Orange County Sanitation District • Gas Holder • Acceptable performance for ground shaking • Piston mechanism is not significantly impacted by seismic loading • Liquefaction-induced lateral spread at the gas holder is not significant • Liquefaction-induced settlement may damage anchorage, which is currently corroded • Strap type anchorage is vulnerable Items for Discussion 64 PS15-06 TM4 Appendix C 290 Orange County Sanitation District P1 Aeration Basins 1-10 65 PS15-06 TM4 Appendix C 291 Orange County Sanitation District P1 Aeration Basins 1-10 66 Vulnerability Potential Mitigation Basins can pull apart at the expansion joints causing large-scale leakage and roof deck collapse. Ground improvement to arrest lateral spread. PS15-06 TM4 Appendix C 292 Orange County Sanitation District P2 Aeration Basins A-H 67 Vulnerability Potential Mitigation Basins can pull apart at the expansion joints causing collapse of the Scott Tunnel roof deck. Ground improvement to arrest lateral spread or deck support extension. PS15-06 TM4 Appendix C 293 Orange County Sanitation District P2 PEPS & MAC 68 PS15-06 TM4 Appendix C 294 Orange County Sanitation District Concrete infill Concrete infill P2 PEPS & MAC 69 Vulnerability Potential Mitigation Shear walls are discontinuous at PEPS basement level. Fill in openings on the north wall at (2) locations to reduce overturning demands on columns below discontinuous shear walls. PS15-06 TM4 Appendix C 295 Orange County Sanitation District P1 City Water Pump Station 70 PS15-06 TM4 Appendix C 296 Orange County Sanitation District Findings – P1 City Water Pump Station 71 Expansion joint at slab Vulnerability Potential Mitigation Building walls are not tied to the floor slab. Add steel angle tie plates between walls and slaF2bs. PS15-06 TM4 Appendix C 297 Orange County Sanitation District P1 Control Center 72 PS15-06 TM4 Appendix C 298 Orange County Sanitation District P1 Control Center 73 Potential fracturing @ shear tab Vulnerability Potential Mitigation Moment frame alignment results in large torsional response of the building. Drifts are estimated to be relatively high. Moment frame connections are pre- Northridge style and cannot develop the flexural capacity of the joints (shear failure can occur). Add steel braced frames and/or concrete shear walls within the plan of the building. PS15-06 TM4 Appendix C 299 Orange County Sanitation District P1 Control Center 74 Weak axis bending Strong axis bending CMCR PS15-06 TM4 Appendix C 300 Orange County Sanitation District P1 Control Center 75 Vulnerability Potential Mitigation Moment frame alignment results in large torsional response of the building. Drifts are estimated to be relatively high. Moment frame connections are pre- Northridge style and cannot develop the flexural capacity of the joints (shear failure can occur). Add steel braced frames and/or concrete shear walls within the plan of the building. PS15-06 TM4 Appendix C 301 Orange County Sanitation District Next Steps 76 PS15-06 TM4 Appendix C 302 Orange County Sanitation District • Present TM3 findings • Continued discussions with OCSD Team • Issue Draft TM3 • Proceed with TM4 • Finalization of Mitigation alternatives • Project prioritization Next Steps 77 PS15-06 TM4 Appendix C 303 Orange County Sanitation District Discussion Discussion 78 PS15-06 TM4 Appendix C 304 Orange County Sanitation District Thank You!Thank You! 79 PS15-06 TM4 Appendix C 305 1-28 to 1-32 4.5 / 5 No LS Structure settlement, inches lateral spread, inches (Best / Upper Estimate, Analysis Water Level) 1-8 3 / 4.5 No LS 1-6 3 / 5 No LS 1-27 4.5 / 5.5 No LS 1-4 3.5 / 5 11-18 / 13-22 1-26 6.5 / 9 13-18 / 22-31 1-11 6 / 8 6-16 / 10-26 1-12 6 / 8 6-38 / 9-56 1-1 6.5 / 8 13-27 / 22-46 1-3 6.5 / 8 26-40 / 34-53 1-9 8.5 / 11 11-12 / 14-16 1-25 6.5 / 8.5 16-150 / 50-165 1-2 4.5 / 7 5-6 / 11-15 1-33 4.5 / 7 No LS 1-16 to 1-20 8.5 / 10 1-16 15-19 / 22-29 1-17 16-17 / 24-26 1-18 14-18 / 21-28 1-19 20-40 / 33-64 1-20 21-29 / 32-45 1-5 7.5 / 9 17-25 / 28-40 1-21A 7.5 / 10 17-35 / 26-52 1-21B 8 / 10 11-16 / 17-24 1-22 8 / 10 13-26 / 19-38 1-23 6 / 7.5 13-20 / 18-29 1-7, 1-10, 1-13 to 15, 1-24 8 / 10 1-7 9-10 / 12-13 1-10 7-8 / 7-9 1-13 9-10 / 9-11 1-14 8-9 / 9-10 1-15 8-9 / 8-9 1-24 10-11 / 11-12 2-21B 2-21A FIGURE NO.:PS15-06 OCSD FOUNTAIN VALLEY CALIFORNIA PLANT 1 LIQUEFACTION INDUCED SETTLEMENT AND LATERAL SPREAD (ANALYSIS WATER LEVEL) DATE:AUGUST 2018 PROJECT NO.: HL1635 Geosyntec CPT Geosyntec Boring Previous CPT Previous Boring LEGEND Free Face ≈ 10 ft Free Face ≈ 15 ft DRAFT PS15-06 TM4 Appendix C 306 FIGURE NO.:PS15-06 OCSD HUNTINGTON BEACH CALIFORNIA PLANT 2 LIQUEFACTION INDUCED SETTLEMENT AND LATERAL SPREAD (ANALYSIS WATER LEVEL) DATE:AUGUST 2018 PROJECT NO.: HL1635 Geosyntec CPT Geosyntec Boring Previous CPT Previous Boring LEGEND DRAFT 2-27 11 / 12 No LS 2-13 11.5 / 13 No LS 2-11 11.5 / 13 No LS 2-6 11.5 / 13 No LS 2-7 11 / 11 15-16 / 17-19 Structure settlement, inches lateral spread (river), inches lateral spread (marsh), inches (Best / Upper Estimate, Analysis Water Level) 2-17 7.5 / 13 12-21 / 16-27 2-29 7.5 / 14 21-92 / 33-145 2-10 5 / 6 No LS 2-8 and 2-28 5 / 6 No LS 2-26 7.5 / 10 No LS 2-9 6 / 7.5 7-8 / 10-11 2-1 6 / 9 7-14 / 15-28 2-2 7 / 9 10-22 / 20-42 2-21 6 / 9.5 8-14 / 13-24 2-22 7.5 / 9 14-28 / 26-52 2-20 7 / 10 6-17 / 7-23 12-66 / 16-77 2-14 to 16, 2-30 13/17 2-14 16-17 / 23-25 2-15 18-19 / 25-27 2-16 17-19 / 25-28 2-30 17-20 / 25-30 2-24 8.5 / 11 45-65 / 65-95 2-31 8 / 10 19-21 / 38-42 6 / 12 2-12 8.5 / 13.5 16-23 / 38-51 9-10 / 21-23 2-5 8.5 / 13.5 19-28 / 28-42 15-17 / 24-26 2-4 3 / 4 1 / 1 1 / 2 2-18A 4 / 5.5 1 / 2-3 1 / 2-3 2-19 3.5 / 4 1 / 1 1 / 2 2-18A 2-18B 2-32 11 / 17 43-75 / 75-130 2-18B 5.5 / 7.5 9-16 / 18-31 9-13 / 18-26 2-3 5.5 / 7.5 13-16 / 18-31 11-13 / 21-25 PS15-06 TM4 Appendix C 307 \Mtg Minutes - OCSD 8-27-18 M EE TING M INUTES SUBJECT: PS15-06 Technical Exchange Meeting #3 DATE: Monday, August 27, 2018 TIME: 9:00 a.m. PST LOCATION: OCSD Administration Building, Engineering Conference Room MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt (via phone), Jackee Almond (via phone) Carollo – James Doering InfraTerra (via phone) – Ahmed Nisar, Nick Doumbalski OCSD – Don Cutler, Mike Lahlou, Eros Yong, Nasrin Nasrollahi Jacobs (via phone) – Elias Mageaes, Kirk Warnock, Jeong Yang 1. Introduction/Safety Moment Conkle presented safety moment. Topic: Hard Hat types and replacement considerations. 2. Discuss Results of Structural Evaluations and Mitigations Aeration Basins Doering: Plant 1 aeration basins: • Two expansion joints, north-south direction • Base of foundation at elevation 10 ft., below grade a fair amount • Water-bearing structure, similar to a concrete building • Basins have the potential to pull apart at the expansion joints • Issue 1A - leakage at basins 3 & 7 • No reinforcing steel across the joint • Issue 1B - roof deck sitting on top of wall will collapse into basin Question from Lahlou: Are you considering the effects of a couple feet of sloshing? PS15-06 TM4 Appendix C 308 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 2 Doering: We are considering it. In this situation it’s not a problem, but those are the kind of things we are looking at. Question from Warnock: Is there no rebar on the joints in the roof? Doering: There is no rebar in the expansion joints. Discussion of Expansion Joint Details Doering: Discussion of Expansion Joint Details. Roof deck sits on top of the wall, bearing on a 3 ¾” wide lip. If this thing stretches out 8 inches, anticipate a collapse or significant damage to the deck. Cutler asked a question about mechanisms for lateral spreading. Hunt: Provided a discussion of the lateral spreading mechanisms at Plant 1 and identified the continuous liquefying the layer below the digesters. Warnock: Are details similar for the bottom slab to the vertical walls? Doering: The joint at the wall is similar to the T-5 detail, but with no expansion joint. Dicusssion of Mitigation Option for P1 Aeration Basin • Issue 1A Structural - tie plate at deck level, restraining the element to the tie. Lahlou: This is mitigation for an existing structure. If you were designing as a new structure, wouldn’t rely on this sort of mitigation, correct? Warnock: The joint was for drying shrinkage. The structure is done with that. What if you tied the slabs? Doering: Once you do get above grade, you will still have thermal expansion. Those expansion joints are really moving. Mageaes: What about in compression, would there be damage to the concrete joints? Doering: No damage in compression. Lahlou: What if there is incidental compression? PS15-06 TM4 Appendix C 309 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 3 Doering: There may be in areas. Warnock: Try to tie the whole structure together. Nisar: We did some calculations for the similar condition on the Secondary Clarifiers. We put in reinforcement, and ran an analysis for it. Need a beefy W-section to hold the structure together, it goes into the plastic range. We are continuing to evaluate it. Yang: How much differential settlement if lateral spreading is removed? Doumbalski: Differential settlement is 40% of total settlement Discussion of Issue 1B • Structural approach: Allow the roof deck to move with new support • Geotechnical Approach: Arrest lateral spread Peps/MAC at Plant 2 Doering: This is Cast in place concrete. Neither structure has piles. Soil anchors to reduce uplift. • Issue 1 – Discussion of column crushing in the wet wellMitigation - reduce the load on that shear wall significantly. Concrete infill at opening. Cutler: Concrete would be needed? Are tie rods not enough? Doering: No, need concrete infill. Previously there was a tie rod mitigation done. • Issue 2 - Soil anchors. Some reduction in uplift capacity. May not know if there is damage to the anchors. Still have a good amount of capacity. Warnock: This is a discontinuous shear wall, not a soft story. PS15-06 TM4 Appendix C 310 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 4 Plant 1 City Water Pump Station Doering: Highlights of the structure - reinforced masonry. • Discussion of Issue 1 Doering: Tie the floor slab to the wall. Warnock: Wouldn’t the bolts just pull out? Doering: Want all three of the elements tied together. Warnock: Tie the wall to the slab. Do it with an angle? Doering: Can do it with an angle. Warnock: Not questioning the need to tie the building together, only about a 2” clearance. Could do that with a concrete curb. Mageaes: Might be limited by the masonry. Fill it every 40 inches. Doering: This is concrete-filled masonry. How much force transfer? Hunt: The difference in lateral spreading between the front and the back of the structure is small; the footprint is small. • Discussion of Issue 2 Doering: There is a heavy wall. With a light frame roof. Roof beams sitting on pilasters taking all that anchorage. Roof deck not taking much. Mitigation: Go with a thru bolt, tie the beams to the walls. Warnock: Did you check out of plane when the roof deck ties in? Doering: Wall anchorage is good, evaluated through Tier 1. Doering: Issue 3 - Based on Tier 3 analysis if the building is subjected to differential settlement, increased bending moments on the wall. This can be mitigated by installing vertical steel. Doering: Issue 4: Pier seeing excessive shear stresses. One solution may be to fiber-wrap the pier. PS15-06 TM4 Appendix C 311 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 5 Lahlou: There was a previous retrofit. Why didn’t anyone address the walls? Doering: This was not picked up in the previous evaluation – wall anchorage only. Control Center Doering: Moment frame structure. Basement level - CIP concrete. Supported on piles. There is a significant torsion issue based on the difference between the CM and CR. Strong vs weak axis. Doering: Mitigation - Add braced frame or shear walls. Yong: What kind of damage may be expected? Doering: Windows blown out, permanent deformation. Potential for collapse. Lahlou: This is immediate occupancy structure. Doering: This is immediate occupancy structure, but it also has the potential for a life safety issue. Lahlou: Is there a liquefaction issue? Doering: We don’t see a concern for geo-seismic. Doering: This is a pre-Northridge Steel moment frame building. Can’t develop shear to develop the ductile behavior of the beam. Mitigation is to add steel braced frames - better than getting into each connection. Mageaes: As you are going through these analyses; do you now have the magnitude of these forces? Doering: We will run numbers to support the cost estimate. PS15-06 TM4 Appendix C 312 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 6 Digesters Nisar: Provided a summary of the evaluations of the Digesters. Warnock: Discussing the evaluation of piles: prestressing force is added to the compression force as well as a gravity load. What is the force? Doumbalski: 75% of yield, then you lose some of it. Use 100-kip axial force in the piles. Warnock: Are you considering impulsive and convective loads. Nisar: Yes Yang/Nisar: Discussion of performance level for structure. Hunt: Liquefaction evaluation is done at 975 year return period level. Nisar: For the mitigation there is not a structural solution, only a geotechnical solution. Ground improvement reduces deformation to 9-12 inches. Discussion of loading on digesters and related evaluations Yang: The sloshing effect is force controlled. Nisar: Sloshing load is increased due to force control, apply it into the same model, convective. Doumbalski: Sloshing mode is the same. Yang: What is height of sloshing? When the dynamic analysis is run, what is the distribution? Doumbalski: In the finite element model - distribute the mass over 20 nodes. For each node, apply different stiffness springs. Lahlou: Did you look at the impact of sloshing on the dome or the connection of the dome to the wall? Nisar: This calculation still needs to be completed. Don’t think that is a controlling mode, but we are doing a calculation for completeness PS15-06 TM4 Appendix C 313 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 7 Yang: Overturning in the piles will be large; the sloshing height is a lot higher. Warnock: We will take a look at the pile analysis when it is completed. Nisar: We have a model with the piles built into it, two separate analyses. Doumbalski provided a discussion of the three separate models used in the evaluation. Warnock: How about pinning the piles to the slab? Yang: Need to make sure the approaches are appropriate. Nisar: Is there anything else that you need to review? Lahlou: The idea is to present the final results of the calculation and assumptions. Lahlou: The digesters were built in several phases by different contractors; Digester 9 is different than the other structures. Nisar: Digester 9 – the reinforcement ratio in the dome is similar, comparing the hoop stresses in the wall. Doumbalski: We have scaled the reinforcement ratio. Warnock: The Tier 1 on these digesters assumes the reinforcing steel in good condition? Nisar: Correct. We didn’t see anything in AECOM’s report that showed condition issues. Lahlou: There are issues on the dome, look at 7, 8, 9, and 10. Did some grouting on the side wall Hunt: We have done our evaluation using the best estimate. Recommendations may indicate the need for further investigation if appropriate in our judgement. Conkle: Make appropriately conservative assumptions, carry forward with that assumption. Secondary Clarifiers Nisar reviews slides. Discussion of structural upgrade option. 3. Questions/Discussion Warnock: We are headed down the right path. PS15-06 TM4 Appendix C 314 PS15-06 Technical Exchange Meeting #3 August 27, 2018 Page 8 Action Items: • Geosyntec to prepare meeting minutes. Attachments • PowerPoint slides from Presentation 8-27-18. * * * * * PS15-06 TM4 Appendix C 315 Orange County Sanitation District Orange County Sanitation District TECHNICAL EXCHANGE MEETING #3 SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 AUGUST 27, 2018 PRESENTED BY: Geosyntec Team PS15-06 TM4 Appendix C 316 Orange County Sanitation District Agenda •Safety Moment •Discuss Results of Structural Evaluations and Mitigations •Questions/Discussion 2 PS15-06 TM4 Appendix C 317 Orange County Sanitation District Safety Moment 3 •Hard Hats PS15-06 TM4 Appendix C 318 Orange County Sanitation District Safety Moment 4 •Hard Hat Types PS15-06 TM4 Appendix C 319 Orange County Sanitation District Safety Moment 5 •Hard Hat Replacement •Impact or penetration •OSHA does not specify the service life of a hard hat •As a general guideline, manufacturers recommend replacing every 5 years •Replace suspension every 12 months. •Include this in your written risk assessment of PPE on site. PS15-06 TM4 Appendix C 320 Orange County Sanitation District Safety Moment 6 PS15-06 TM4 Appendix C 321 Orange County Sanitation District Meeting Objectives •Discussion of vulnerability findings for additional structures •Preview of mitigation recommendations •Facilitate review of Upcoming Deliverables 7 PS15-06 TM4 Appendix C 322 Orange County Sanitation District Structural Evaluations and Mitigations 8 PS15-06 TM4 Appendix C 323 Orange County Sanitation District Structural Groups 9 Buildings –Shallow Foundations Buildings -Mat Foundation Buildings -Deep Foundations Gas Holders Surge Towers Buried Boxes Secondary Clarifiers Aeration Basins Digesters DAFTs . PS15-06 TM4 Appendix C 324 Orange County Sanitation District P1 Aeration Basins 1-10 10 PS15-06 TM4 Appendix C 325 Orange County Sanitation District P1 Aeration Basins 1-10 11 PS15-06 TM4 Appendix C 326 Orange County Sanitation District P1 Aeration Basins 1-10 12 Issue #Potential Failure Mode Basis Performance 1A Basins pull apart at the expansion joints. Lateral spread – Exemplar Large scale leakage at the affected basins (3 & 7). 1B Basins pull apart at the expansion joints. Lateral spread – Exemplar The roof deck at the expansion joint collapses into the basins (3 & 7). PS15-06 TM4 Appendix C 327 Orange County Sanitation District P1 Aeration Basins 1-10 13 16” 9” 13” 6” PS15-06 TM4 Appendix C 328 Orange County Sanitation District P1 Aeration Basins 1-10 14 PS15-06 TM4 Appendix C 329 Orange County Sanitation District P1 Aeration Basins 1-10 15 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 1A Basins pull apart at the expansion joints causing large- scale leakage. Structural tie across the joint Ground improvement to arrest lateral spread. New tie plate PS15-06 TM4 Appendix C 330 Orange County Sanitation District P1 Aeration Basins 1-10 16 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 1A Basins pull apart at the expansion joints causing large- scale leakage. Structural tie across the joint Ground improvement to arrest lateral spread. Santa Ana RiverDigester Ground Improvement Zone 0.00 0.25 0.50 0.75 1.00 1.25 1.50 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Spe c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (seconds) ASCE 41-13 Horizontal Response Spectra -OCSD Plant 1 -Site Class D Ground Shaking Permanent Ground Deformation PS15-06 TM4 Appendix C 331 Orange County Sanitation District P1 Aeration Basins 1-10 17 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 1B Basins pull apart at the expansion joints causing roof deck collapse. Addition of a supporting shelf Ground improvement to arrest lateral spread. New support PS15-06 TM4 Appendix C 332 Orange County Sanitation District •Aeration Basins •Large lateral spread deformation and settlement results in significant differential movement across expansion joints. •Structurally connecting basins across expansion joints is a potential structural retrofit. Consideration to slotting ties to allow for thermal expansion/contraction. •Ground improvement will reduce lateral spread. P1 Aeration Basins 1-10 -Discussion 18 PS15-06 TM4 Appendix C 333 Orange County Sanitation District P2 PEPS & MAC 19 PS15-06 TM4 Appendix C 334 Orange County Sanitation District P2 PEPS & MAC 20 12 kV Dist BPEPS/MAC PS15-06 TM4 Appendix C 335 Orange County Sanitation District P2 PEPS & MAC 21 Issue #Potential Failure Mode Basis Performance 1 Axial crushing of columns within the wet well. Tier 1 Localized column crushing and instability in the building support. PS15-06 TM4 Appendix C 336 Orange County Sanitation District P2 PEPS & MAC 22 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 1 Axial crushing of columns within the wet well. Fill in openings on the north wall at (2) locations to reduce overturning demands on columns below discontinuous shear walls. N/A Concrete infill Concrete infill PS15-06 TM4 Appendix C 337 Orange County Sanitation District P2 PEPS & MAC 23 Issue #Potential Failure Mode Basis Performance 2 Soil anchors lose uplift capacity Geotechnical Analysis 23 inches of lateral movement. Some reduction in uplift capacity. PS15-06 TM4 Appendix C 338 Orange County Sanitation District P2 PEPS & MAC 24 Issue #Potential Failure Mode Basis Performance 2 Soil anchors lose uplift capacity Geotechnical Analysis 23 inches of lateral movement. Some reduction in uplift capacity. From P2-23-6 Specifications Geotechnical Analysis Ultimate Anchor Capacities (kips) -Unfactored Anchor High W -No Liq High W -Liquef Typ W -No Liq Typ W -Liquef A 46 34 53 39 PS15-06 TM4 Appendix C 339 Orange County Sanitation District •Reduction of lateral load on west shear wall will reduce overturning demands on columns in the PEPS wet well. •Lateral spread may damage soil anchors, which can lead to uplift during seismic event or post seismic event. P2 PEPS & MAC -Discussion 25 PS15-06 TM4 Appendix C 340 Orange County Sanitation District P1 City Water Pump Station 26 PS15-06 TM4 Appendix C 341 Orange County Sanitation District P1 City Water Pump Station 27 PS15-06 TM4 Appendix C 342 Orange County Sanitation District P1 City Water Pump Station 28 Issue #Potential Failure Mode Basis Performance 1 Building walls pull apart from each other. Tier 1 Reduced capacity to resist lateral spread, in-plane shear, and out-of-plane forces. Can result in instability of the building walls. Expansion joint at slab PS15-06 TM4 Appendix C 343 Orange County Sanitation District P1 City Water Pump Station 29 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 1 Building walls pull apart from each other. Tie walls to building slab.N/A PS15-06 TM4 Appendix C 344 Orange County Sanitation District P1 City Water Pump Station 30 Issue #Potential Failure Mode Basis Performance 2 Roof beam anchorage to the CMU wall pulls out (incompatibility w/ deck). Tier 1 Roof beam can collapse if anchors pull-out or masonry wall spalls below anchors. PS15-06 TM4 Appendix C 345 Orange County Sanitation District P1 City Water Pump Station 31 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 2 Roof beam anchorage to the CMU wall pulls out (incompatibility w/ deck). Enhance connection with additional anchors and welded steel connections to beam. N/A PS15-06 TM4 Appendix C 346 Orange County Sanitation District P1 City Water Pump Station 32 Issue #Potential Failure Mode Basis Performance 3 Horizontal bending moments due to shaking and ground deformation exceed the wall capacity. Tier 3 – Differential Settlement Excessive cracking/spalling of wall. PS15-06 TM4 Appendix C 347 Orange County Sanitation District P1 City Water Pump Station 33 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 3 Horizontal bending moments due to shaking and ground deformation exceed the wall capacity. Add vertical steel or concrete pilaster to reduce horizontal spans in wall. N/A PS15-06 TM4 Appendix C 348 Orange County Sanitation District P1 City Water Pump Station 34 Issue #Potential Failure Mode Basis Performance 4 Excessive shear stress in south wall pier. Tier 3 – Differential Settlement Excessive cracking/spalling of wall. PS15-06 TM4 Appendix C 349 Orange County Sanitation District P1 City Water Pump Station 35 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 4 Excessive shear stress in south wall pier. Fiber composite wall overlay. N/A PS15-06 TM4 Appendix C 350 Orange County Sanitation District P1 Control Center 36 PS15-06 TM4 Appendix C 351 Orange County Sanitation District P1 Control Center 37 PS15-06 TM4 Appendix C 352 Orange County Sanitation District P1 Control Center 38 Issue #Potential Failure Mode Basis Performance 1 Building responds with large high drift causing structural and non- structural damage. Tier 1 Building will likely experience large non-linear deformations that will be permanent. Windows, finish materials, and interior appurtenances will experience high levels of damage. Some columns may be near collapse. PS15-06 TM4 Appendix C 353 Orange County Sanitation District P1 Control Center 39 Weak axis bending Strong axis bending CMCR PS15-06 TM4 Appendix C 354 Orange County Sanitation District P1 Control Center 40 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 1 Building responds with large high drift causing structural and non- structural damage. Add steel braced frames and/or concrete shear walls within the plan of the building. N/A PS15-06 TM4 Appendix C 355 Orange County Sanitation District P1 Control Center 41 Issue #Potential Failure Mode Basis Performance 2 Moment frame connections fracture. Tier 1 Potential collapse of beams from their column supports. Potential fracturing @ shear tab PS15-06 TM4 Appendix C 356 Orange County Sanitation District P1 Control Center 42 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 2 Moment frame connections fracture. Add steel braced frames and/or concrete shear walls within the plan of the building. N/A PS15-06 TM4 Appendix C 357 Orange County Sanitation District P1 Control Center 43 Issue #Potential Failure Mode Basis Performance 3 Moment frame uplift from the column base. Tier 1 Damage to the base connection due to uplift can lead to building instability. PS15-06 TM4 Appendix C 358 Orange County Sanitation District P1 City Water Pump Station 44 Issue #Potential Failure Mode Structural Mitigation Geotechnical Mitigation 3 Moment frame uplift from the column base. Add steel braced frames and/or concrete shear walls within the plan of the building. N/A PS15-06 TM4 Appendix C 359 Orange County Sanitation District P1 Control Center 45 Potential fracturing @ shear tab Vulnerability Potential Mitigation Moment frame alignment results in large torsional response of the building. Drifts are estimated to be relatively high. Moment frame connections are pre- Northridge style and cannot develop the flexural capacity of the joints (shear failure can occur). Add steel braced frames and/or concrete shear walls within the plan of the building. PS15-06 TM4 Appendix C 360 Orange County Sanitation District P1 Control Center 46 Vulnerability Potential Mitigation Moment frame alignment results in large torsional response of the building. Drifts are estimated to be relatively high. Moment frame connections are pre- Northridge style and cannot develop the flexural capacity of the joints (shear failure can occur). Add steel braced frames and/or concrete shear walls within the plan of the building. PS15-06 TM4 Appendix C 361 Orange County Sanitation District Digesters 47 PS15-06 TM4 Appendix C 362 Orange County Sanitation District 48 11 12 13 14 15 16 6 7 8 9 10 5 35” 17” 16”11” PS15-06 TM4 Appendix C 363 Orange County Sanitation District Foundation Plan 49 Diameter = 110 ft PS15-06 TM4 Appendix C 364 Orange County Sanitation District 50 Plant 1 Digester 16 Idealized Soil Profile Historic High Typical Settlement (inches) Santa Ana River H = 10 ft Near Distance = 41 ft Far Distance = 155 ft Far Lateral Spread (inches)Near Lateral Spread (inches) Idealized Soil Profile W E 0.00 0.25 0.50 0.75 1.00 1.25 1.50 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Spe c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (seconds) ASCE 41-13 Horizontal Response Spectra -OCSD Plant 1 -Site Class D Ground Shaking Permanent Ground Deformation PS15-06 TM4 Appendix C 365 Orange County Sanitation District 51 11 12 13 14 15 16 6 7 8 9 10 5 35” 17” 16”11” Digester Piles 21 inches Front Row Back Row 24 inches PS15-06 TM4 Appendix C 366 Orange County Sanitation District Earthquake Damage –1995 Kobe, Japan 52 Concrete piles supporting digester closest to channel cracked at the top Differential settlement between pile supported digester and adjacent ground PS15-06 TM4 Appendix C 367 Orange County Sanitation District Digester 16 (Exemplar) Potential Failure Modes 53 Description Ground shaking (GS) - Failure of dome-wall connection Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description GS - Failure of dome Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description GS - Hoop stress failure in wall Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description GS - Out-of-plane bending/shear in wall Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description GS - Punching of mat Status Analysis Completed, DCR<m, Failure not likely. Punching capacity of mat is higher than the pile capacity. Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description GS - Vertical failure of piles Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description GS - Bending/shear failure of piles Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Linear Finite Element Response Spectrum Analysis. Description Punching of mat due to liquefaction Status Analysis Completed, DCR<m, Failure not likely Evaluation Approach Nonlinear Pushover Finite Element Analysis. Description Vertical failure of piles due to lateral spread Status Analysis Completed. Vertical load in some piles exceeds the capacity. Pile load redistribution. No global failure Evaluation Approach Nonlinear Pushover Finite Element Analysis. Description Bending/shear failure of piles due to lateral spread. Best estimate lateral spread is 35-inches for Analysis Ground Water Level Status Analysis Completed. Bending moment in piles will exceed the capacity at around 24-inches of lateral spread. Evaluation Approach Nonlinear Pushover Finite Element Analysis. Description Vertical failure of piles due to settlements Status Analysis Completed. Vertical load in some piles exceeds the capacity. Pile load redistribution. No global failure Evaluation Approach Nonlinear Pushover Finite Element Analysis. PFM7 PFM8 PFM9 PFM10 PFM11 PFM1 PFM2 PFM3 PFM4 PFM5 PFM6 PS15-06 TM4 Appendix C 368 Orange County Sanitation District •Evaluation Approach for Digesters •Tier 3 for Digester 16 •Tier 1 “Modified” for other structures based on the results of Tier 1 Digesters –Plant 1 54 Di g e s t e r Nu m b e r of p i l e s Sh e l l Di a m e t e r ( f t ) Ar e a p e r Pi l e (s f t ) Sh e l l Th i c k n e s s (i n ) Sh e l l He i g h t (f t ) Do m e Ra d i u s (f t ) Do m e Th i c k n e s (i n ) Di s t a n c e fo r m Ri v e r ( f t ) Do m e Re i n f o r c e m e n t Ra t i o Ve r t i c a l W a l l Re i n f o r c e m e n t Ra t i o Ho r i z o n t a l W a l l Re i n f o r c e m e n t Ra t i o Comparison to Digester 16 Digester 5 251 90 25 19 30.5 75 5 400 0.68% 0.32% 1.40% Smaller than D16, further from river Digester 6 251 90 25 22 30.5 Steel 1/4"500 N/A 0.32% 1.43% Smaller than D16, further from river, steel dome Digester 7 280 90 23 22 30.5 75 5 250 1.07% 0.57% 1.52% Smaller than D16, further from river Digester 8 280 90 23 22 30.5 75 5 300 0.93% 0.57% 1.44% Smaller than D16, further from river Digester 9 242 110 39 27 31.5 108.5 6 100 0.43% 0.27% 1.45'% Similar to D16, fewer piles Digester 10 242 110 39 27 31.5 108.5 6 100 0.43% 0.27% 1.45'% Similar to D16, fewer piles Digester 11 280 110 34 27 31.5 108.5 6 250 0.43% 0.48% 2.02% Identical to D16, further from river Digester 12 280 110 34 27 31.5 108.5 6 250 0.43% 0.48% 2.02% Identical to D16, further from river Digester 13 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Identical to D16 Digester 14 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Identical to D16 Digester 15 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Identical to D16 Digester 16 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Exemplar PS15-06 TM4 Appendix C 369 Orange County Sanitation District •Digesters •Piles for front row of digesters closest to the river (7-12) are vulnerable to significant damage •Piles for back row of digesters will deform but maintain capacity •Reduction of lateral spread displacement through ground improvement will improve seismic performance of digesters Items for Discussion 55 PS15-06 TM4 Appendix C 370 Orange County Sanitation District •Ground improvement options to limit lateral spread Digesters –Lateral Spread Mitigation 56 Santa Ana RiverDigester Ground Improvement Zone 0.00 0.25 0.50 0.75 1.00 1.25 1.50 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Spe c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (seconds) ASCE 41-13 Horizontal Response Spectra -OCSD Plant 1 -Site Class D Ground Shaking Permanent Ground Deformation PS15-06 TM4 Appendix C 371 Orange County Sanitation District •Option 1: Ground improvement to limit lateral spread •Construct ground improvement shear panels •Ground improvement methods: Auger soil mixing, cutter soil mixing, slurry wall method, jet grouting, … •Key ground improvement elements: •Large footprint (utility relocation, surface disruptions) •Must achieve high strength and/or large “replacement volume” •“Key” improvement below lateral spread zone (Digesters~ Elev. -10 feet) Lateral Spread Mitigation Concepts 57 PS15-06 TM4 Appendix C 372 Orange County Sanitation District •Option 2: Subsurface retaining wall to limit lateral spread •Design wall to resist earth pressure from lateral spread without excessive deflection –soil “in front” of wall would still move away •Wall types: secant pile wall, cutter soil mix wall, … •Key wall elements •Smaller footprint •Significant depth (~100 ft), founded below liquefaction zone •Heavily reinforced to limit deflections Lateral Spread Mitigation Concepts 58 PS15-06 TM4 Appendix C 373 Orange County Sanitation District •Secant Pile Wall Installation Digesters –Lateral Spread Mitigation 59Image Source: Hayward BakerPS15-06 TM4 Appendix C 374 Orange County Sanitation District Secondary Clarifiers 60 PS15-06 TM4 Appendix C 375 Orange County Sanitation District Secondary Clarifiers 61 Expansion Joints 44” 32” 32” 29” 10” 11” 12” 16” PS15-06 TM4 Appendix C 376 Orange County Sanitation District Secondary Clarifiers FE Model PS15-06 TM4 Appendix C 377 Orange County Sanitation District Secondary Clarifiers 63 Lateral Spread Settlement PS15-06 TM4 Appendix C 378 Orange County Sanitation District Earthquake Damage –1995 Kobe, Japan 64 Expansion joint separation along entire bank Damage to sludge scraper chains Damage to water stops PS15-06 TM4 Appendix C 379 Orange County Sanitation District Earthquake Damage –1995 Kobe, Japan 65 Effluent channel offset nearly 1m from lateral spread Building movement PS15-06 TM4 Appendix C 380 Orange County Sanitation District Secondary Clarifiers Structural Upgrade Option 66 W12x196 Beams Added (longitudinal direction)W12x196 Beams Added (transverse direction) PS15-06 TM4 Appendix C 381 Orange County Sanitation District •Option 1: Secant pile wall to limit lateral spread towards marsh, but not control settlement •Option 2: Ground improvement below clarifiers to limit both settlement and lateral spread •Either option would stabilize lateral spread towards marsh for structures “behind” clarifiers as well Secondary Clarifiers –Geotech Mitigation 67 PS15-06 TM4 Appendix C 382 Orange County Sanitation District •Secant Pile Wall Installation along River and Marsh Lateral Spread Mitigation –Plant 2 Concept 68 •Lateral Spread “cutoff” wall •May need to be installed outside property line •Can be locally stopped or shifted back where utilities cross •Will not mitigate settlementPS15-06 TM4 Appendix C 383 Orange County Sanitation District •Secondary Clarifiers •Large lateral spread deformation and settlement results in significant differential movement across expansion joints •Structurally connecting clarifiers across expansion joints is a potential structural retrofit •Ground improvement will reduce lateral spread but impractical to reduce settlements •Ground improvement together with structural retrofit would improve seismic performance Items for Discussion 69 PS15-06 TM4 Appendix C 384 Orange County Sanitation District Surge Tower 70 PS15-06 TM4 Appendix C 385 Orange County Sanitation District Surge Tower 2 71 65” PS15-06 TM4 Appendix C 386 Orange County Sanitation District 65” Surge Tower 2 72 PS15-06 TM4 Appendix C 387 Orange County Sanitation District Surge Tower 2 73 PS15-06 TM4 Appendix C 388 Orange County Sanitation District Surge Tower 2 74 PS15-06 TM4 Appendix C 389 Orange County Sanitation District Surge Tower 2 75 Expansion Joint PS15-06 TM4 Appendix C 390 Orange County Sanitation District Surge Tower 76 Dresser coupling will disengage due to differential movement PS15-06 TM4 Appendix C 391 Orange County Sanitation District Surge Tower 2 77 Mode shape Tilt from settlementPS15-06 TM4 Appendix C 392 Orange County Sanitation District •Surge Towers •Acceptable performance for ground shaking •Liquefaction-induced lateral spread will result in sliding, which will significantly damage connection with outfall pipeline •Liquefaction-induced settlement causes minor tilting Items for Discussion 78 PS15-06 TM4 Appendix C 393 Orange County Sanitation District Gas Holder 79 PS15-06 TM4 Appendix C 394 Orange County Sanitation District Gas Holder 80 PS15-06 TM4 Appendix C 395 Orange County Sanitation District Gas Holder 81 PS15-06 TM4 Appendix C 396 Orange County Sanitation District •Gas Holder •Acceptable performance for ground shaking •Piston mechanism is not significantly impacted by seismic loading •Liquefaction-induced lateral spread at the gas holder is not significant •Liquefaction-induced settlement may damage anchorage, which is currently corroded •Strap type anchorage is vulnerable Items for Discussion 82 PS15-06 TM4 Appendix C 397 Orange County Sanitation District Discussion 83 PS15-06 TM4 Appendix C 398 Orange County Sanitation District Thank You! 84 PS15-06 TM4 Appendix C 399 \Mtg Minutes 4-26-18 MEETING MINUTES SUBJECT: PS15-06 Technical Exchange Meeting DATE: Wednesday, April 26, 2018 TIME: 9:30a.m. PST LOCATION: Geosyntec Oakland Office 1111 Broadway Street, 6th Floor, Oakland, CA, 94607, USA MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering InfraTerra – Ahmed Nisar, Nick Doumbalski OCSD – Don Cutler (Phone), Mike Lahlou Jacobs – Elias Mageaes (Phone), Kirk Warnock, Jeong Yang 1. Introduction/Safety Moment Chris Hunt provided a safety moment regarding building evacuation. Don Cutler provided an introduction. He indicated that the main purpose of the meeting was to get everyone on same page in terms of how we are conducting structural evaluations and how we use standards for non-building structures. (How to integrate the standards into this study). This meeting was also used as a time to update Jacobs as the technical reviewer and to get them familiar with the evaluation approach and solicit their feedback. PS15-06 TM4 Appendix C 400 PS15-06 Technical Exchange Meeting April 26, 2018 Page 2 Conkle summarized the meeting objectives as follows: • Provide “in progress” update on Task 3. • Answer questions regarding approach. • Facilitate review of Upcoming Deliverables. 2. Discussion of Overall PS15-06 Objectives and Summary of Geotechnical Hazards Conkle provided a description of the study objectives and the geotechnical evaluations completed to date which are important inputs to the structural approach to be discussed today and ultimately the development of mitigation measures. A summary of liquefaction and lateral spread show potential for both at Plant 1 and Plant 2 was presented (see slides). Cutler: Does free face consider structural resistance of the channel wall? Conkle: It does not. It is not included in the empirical models for lateral spread, and we assume that it was not designed to manage the deformations associated with lateral spread Mageaes: Is the variation in settlement and lateral spread shown in the figures common? Hunt : Not uncommon at all in the depositional environment (river deposits). Cutler: Is the 25 inches of settlement at CPT-05 due to lateral spread or surface settlement? Is it possible that CPT-05 is an anomaly? Conkle: This is level ground settlement that does not account for lateral spread. Hunt: Each of the estimates is based on conditions encountered at that specific location. We will review the investigations surrounding each location when making the final recommendations. 3. Description of Tiered Structural Evaluation Approach Conkle provided a description of the Tiered approach to structural evaluations using ASCE 41-13 as a framework. Evaluations for non-typical structures and those structures exposed to liquefaction will require a Tier 3 evaluation or a modified Tier 1 or modified Tier 2 evaluation. Tier 2 and Tier 3 will be sequential. Even if the deformations are very high PS15-06 TM4 Appendix C 401 PS15-06 Technical Exchange Meeting April 26, 2018 Page 3 and we anticipate damage, the teams will perform the analysis to inform risk and mitigation for the specific structure and others like it. (See slides.) Cutler: If we have a structure w/ deep foundation, do we need a Tier 3? Conkle: We need to use Tier 3 for the exemplar structures where liquefaction is present. Nisar: We are using ASCE 41 as a framework, but not tying ourselves to strict code compliance w/ ASCE 41 because we have non-typical conditions, but we want to have a good understanding of structural behavior and apply an approach to it. ASCE 41 tiers are not necessarily sequential. For the Digesters, we may be able to justify de-coupling above-ground from below-ground response. Lahlou: If you are not using ASCE 41 directly for everything, what is the criteria for these other checks? Nisar: We will take most appropriate methodologies from the standards/codes and adjust them as needed to move forward. Warnock: In your Tier 1 evaluations for non-building structures, are you creating something similar to the Tier 1 ASCE 41-13 checklists? Nisar: We are not developing a code, but each structure will have detail about how it was analyzed and worked through. Action: Jacobs requested an example of the “Tier 1” approach for liquid containing structures when it is available for review from the Geosyntec team. Warnock: Why is a Tier 3 being done with liquefaction-induced settlement of 10 inches below a clarifier. This is a lot, and it would seem that the battle is lost to begin with. Conkle: This first pass accounts for liquefaction without site unmitigation. The approach is to not write off a structure before understanding its performance as best as we can. One thing we are trying to avoid is to just call for ground improvement. This approach appears appropriate based on the initial set of structures evaluated. Warnock: Understood. Post-grout to raise structure might be an option to plan for. Cutler: What is the risk of the lateral spread/settlement identified? PS15-06 TM4 Appendix C 402 PS15-06 Technical Exchange Meeting April 26, 2018 Page 4 Conkle: The settlement and lateral spread indicated have a likelihood consistent with the design earthquake identified in TM-1 4. Example Structure at Plant 1 – Digester 16 Nisar and Hunt provided a discussion of the evaluations at Digester 16 with highlights as follows. (See attached slides.) Neither ASCE 41-13 or ACI 350.3 can be strictly applied to the digester, but we are using their guidance as the best available. The soil settlements/deformations are based on review of CPTs in the region of the structure and judgment of the geotechnical engineers. Assumed groundwater levels considered are important to the deformations that are developed Resistance due to connected pipelines are ignored. OCSD recognizes that utility connections are critical, but the focus of the study is on the structures, and the prioritization of structures will likely help to guide when work is done on connections as part of future projects. Lahlou: Did you look at buoyancy for the digester? Doumbalski: Piles are designed for 50 kip of uplift. We assumed that the digester was full. Yang: Is this a linear dynamic response? Nisar: Yes. Response spectra only allows for linear. Structure above the base is basically linear, so don’t see a need for non-linear analysis. Mageaes: Soil profile is all liquefiable? No zones? Hunt: We are doing an evaluation using CPT’s, and we develop a profile. It is not uniformly liquefiable. Springs consider the profile. (CH) Cutler: Any issues with the proposed approach (to Jacobs)? Yang: You have to define which one is deformation controlled and which one is force controlled. The chart you show is only showing for deformation-controlled member. It is hard to define force-controlled vs deformation-controlled member for liquid containing members. PS15-06 TM4 Appendix C 403 PS15-06 Technical Exchange Meeting April 26, 2018 Page 5 Nisar and Doumbalski: Different m-factors can be used for various elements. It appears we have good detailing. If nothing is available, we can demonstrate through a moment-curvature analysis to estimate ductility and use our judgment. Lahlou (summarizing): The m-factor will depend on the structure. There will be a lot of assumptions. We can discuss and document them in detail when review each structure 5. Example Structure at Plant 2 – PEPS/MAC Doering provided a discussion of the evaluations undertaken thus far at PEPS/MAC, including the results of the Tier 1 and initial discussion of the planned Tier 3. (See slides.) PEPs/MAC employed ASCE 41-13 directly for Tier 1 due to strong shaking based on good as-built information. Have identified some non-compliant items, including vertical irregularity of shear walls. The Tier 3 evaluation presented is ongoing. Mageaes: You have assumed free-field conditions. How do other structures influence? What are your thoughts? Hunt: Free-field for lateral spread is conservative. We may consider shielding as part of the mitigation development. 6. Summarize Path Forward for Other Structures Warnock: Jacobs agrees with the approach to do Tier 3 to exemplar structures as described here. Yang: Complexity of ground deformation issues have come about since TM1. We understand that Geosyntec will issue a final TM1 in the near future. Mageaes: This was an excellent discussion. All have done great work. Feel free to move forward with any work you have planned in the near future Cutler: I want to make sure that the Geosyntec Team has enough leeway and flexibility to approach evaluations as they see fit. Warnock: The evaluations presented are very transparent. Impressed by the progress made by the Geosyntec team. PS15-06 TM4 Appendix C 404 PS15-06 Technical Exchange Meeting April 26, 2018 Page 6 Action Items: • Geosyntec to prepare meeting minutes. • TM-1 will be issued addressing the comments received thus far. Additional detail regarding approach, including items discussed in this meeting, will be documented in TM-3. • Further discussion is needed on how we choose deformation-controlled vs force- controlled for structural checks. This discussion will happen in meetings specific to the evaluation of each structure. ***** Attachments • PowerPoint slides from Presentation 4-26-18 PS15-06 TM4 Appendix C 405 Orange County Sanitation District Orange County Sanitation District TECHNICAL EXCHANGE MEETING SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 APRIL 26, 2018 PRESENTED BY: Geosyntec Team PS15-06 TM4 Appendix C 406 Orange County Sanitation District Agenda • Discussion of Overall PS15-06 Objectives and Summary of Geotechnical Hazards • Description of Evaluation Approach • Example Structure at Plant 1 – Digester 16 • Example Structure at Plant 2 – PEPS/MAC • Summarize Path Forward for other structures • 11:30 Questions/Discussion • 12:00 Lunch • 12:30 – 2:00 Continue Discussion 2 PS15-06 TM4 Appendix C 407 Orange County Sanitation District Safety Moment 3 • Building Evacuation Notes PS15-06 TM4 Appendix C 408 Orange County Sanitation District Introductions •The Geosyntec Team: –Chris Conkle – Chris Hunt – James Doering (Carollo) – Structural Lead – Ahmed Nisar (InfraTerra) – Structural Lead •OCSD Team: –Don Cutler –Mike Lahlou –Jacobs 4 PS15-06 TM4 Appendix C 409 Orange County Sanitation District Meeting Objectives •Provide “in progress” update on Task 3 •Answer questions regarding approach •Facilitate review of Upcoming Deliverables 5 PS15-06 TM4 Appendix C 410 Orange County Sanitation District Project Objectives/Summary of Geotechnical Hazards 6 PS15-06 TM4 Appendix C 411 Orange County Sanitation District Introduction – Project Objective - Conkle •Planning Level Study •Identification of critical structural vulnerabilities •Not code compliance •Develop retrofit recommendations to be incorporated into facility master plan. •Requires consistent basis amongst building and non building structures 7 PS15-06 TM4 Appendix C 412 Orange County Sanitation District Geotechnical Evaluation Elements 8 •Site cross‐sections and individual structure soil profiles •Liquefaction settlement and lateral spread based on empirical tools •For Tier 3 analyses develop –Axial and lateral pile capacities –Shallow foundation lateral resistance –Earth pressures on buried structures –Soil Springs •Develop mitigation measures PS15-06 TM4 Appendix C 413 Orange County Sanitation District Liquefaction and Lateral Spreading 9 PS15-06 TM4 Appendix C 414 Orange County Sanitation District Liquefaction and Lateral Spreading 10 PS15-06 TM4 Appendix C 415 Orange County Sanitation District Liquefaction and Lateral Spreading 11 PS15-06 TM4 Appendix C 416 Orange County Sanitation District CPT-15 (4.9 in) 0.5 ft 12 CPT-17 (10.2 in) 4.3 ft Free Face≈ 10 ft Free Face≈ 15 ft CPT-16 (12.6 in) 1.6 ft CPT-04 (7.7 in) 4.1 ft CPT-14 (8.5 in) 1.4 ft CPT-03 (11.7 in) 1.5 ft CPT-13 (6.0 in) 0.2 ft CPT-11 (10.8 in) 1.2 ft CPT-10 (12.4 in) 2.7 ft CPT-06 (5.4 in) 0.3 ft CPT-01 (5.1 in) 0.2 ft CPT-05 (5.4 in) 0.2 ft CPT-12 (9.7 in) 0.7 ft CPT-09 (7.4 in) 1.8 ft CPT-02 (9.2 in) 1.6 ft CPT-07 (5.8 in) 4.2 ft CPT-08 (6.0 in) 1.8 ft CPT-XX (settlement, inches) lateral spread, feet Plant 1 Estimated Liquefaction- Induced Settlement and Lateral Spread PS15-06 TM4 Appendix C 417 Orange County Sanitation District 13 Plant 2 Estimated Liquefaction- Induced Settlement and Lateral Spread at 2018 CPT Investigation Locations CPT-XX (settlement, inches) lateral spread SA, feet lateral spread TM, feet CPT-03(13.1 in)1.4 ft0.3 ft CPT-04(13.3 in)0.8 ft0.6 ft CPT-05(24.8 in)12.7 ft1.2 ft CPT-01(12.5 in)2.5 ft0.5 ft CPT-02(8.5 in)2.6 ft0.5 ft CPT-09(6.0 in)1.3 ft2.9 ft CPT-08(8.8 in)1.7 ft1.3 ft CPT-07(11.2 in)4.5 ft1.4 ft CPT-06(5.9 in)0.5 ft0.3 ft CPT-10(4.2 in)0.2 ft0.4 ft CPT-11(8.9 in)0.5 ft3.8 ft PS15-06 TM4 Appendix C 418 Orange County Sanitation District Description of Evaluation Approach (Application of ASCE 41-13 to Buildings and Non-Building Structures with Liquefaction) 14 PS15-06 TM4 Appendix C 419 Orange County Sanitation District Structural Evaluation Approach – Conkle • Philosophy consistent ASCE 41-13: – In‐depth evaluation of vulnerabilities based on Tier 3 – Project‐specific application to similar structures (Tiered approach) – Extending industry experience with structural performance in these areas 15 PS15-06 TM4 Appendix C 420 Orange County Sanitation District Structural Evaluation Approach - Tier 1 •Tier 1 Screening Procedure •Evaluation only •Quick screening tool •Summary data sheet •Utilize checklists •Outcome – list of potential deficiencies 16 Building Structures Liquid Containing Structures Data Forms ASCE 41-13 Tier 1 PS15-06 TM4 Appendix C 421 Orange County Sanitation District Structural Evaluation Approach - Tier 2 Tier 2 Deficiency Based Procedure – Buildings •Evaluation and retrofit •Examine Tier 1 deficiencies only •May mitigate Tier 1 deficiencies by calculations or retrofit •No “direct” route to Tier 2 where liquefaction is present 17 Building Structures ASCE 41-13 Tier 1 Liquefac tion ? No Perform. OK? No ASCE 41-13 Tier 2 Perform. OK? Yes ASCE 41-13 Tier 3 Exemplar Building Approach PS15-06 TM4 Appendix C 422 Orange County Sanitation District Structural Evaluation Approach - Tier 2 Tier 2 Deficiency Based Procedure – Liquid Containing Structures •Non Typical Building Types – No “direct” route to Tier 2 •Liquefaction Present ‐ No “direct” route to Tier 2 18 Liquid Containing Structures Common Building? Perform. OK? YesData Forms No No ASCE 41-13 Tier 2 Perform. OK? ASCE 41-13 Tier 3 Exemplar Building Approach PS15-06 TM4 Appendix C 423 Orange County Sanitation District Structural Evaluation Approach - Tier 3 •Tier 3 ‐ Systematic procedure –Account for response of the entire soils/structure system –3D finite‐element model –Modeling of foundation support –Use directly to develop retrofit options –Account for the range of geotechnical conditions and uncertainty in the selection of inputs 19 PS15-06 TM4 Appendix C 424 Orange County Sanitation District Structural Evaluation Approach •Exemplar Structures Approach ‐ Requires Tier 3 •Account for the range of geotechnical conditions and uncertainty in the selection of inputs 20 Exemplar Tier 3 to Calibrate Response Estimate Upper Bound Response Estimate Lower Bound Response Informs Tier 1/2 for similar structures PS15-06 TM4 Appendix C 425 Orange County Sanitation District Structural Evaluation Approach - Buildings •Exemplar Buildings w/ Liquefaction 21 Exemplar Building Structures ASCE 41-13 Tier 3 Perform. OK? No Yes FEM Apply Results to other similar Building Structures Develop Retrofit Recommendation PS15-06 TM4 Appendix C 426 Orange County Sanitation District Structural Evaluation Approach - Buildings •Additional Buildings w/ Liquefaction 22 Building Structures ASCE 41-13 Tier 1 ASCE 41-13 Tier 1 Modified Similar Config to Tier 3? No ASCE 41-13 Tier 2 Modified Yes Perform. OK? No Yes Develop Retrofit Recommendation Evaluation Complete •Tier 1 Modified •Compare loading and configuration to similar exemplar Tier 3 •Make assessment of performance based on Tier 3 •Tier 2 Modified •Confirm sufficiently dissimilar from exemplar Tier 3 •Perform simplified calculations that serve as basis of comparison to exemplar Tier 3 analysis Perform. OK? No Develop Retrofit Recommendation Evaluation Complete PS15-06 TM4 Appendix C 427 Orange County Sanitation District Structural Evaluation Approach - Liquid Containing Structures •Exemplar Structures w/ Liquefaction 23 Exemplar Liquid Containing Structures ASCE 41-13 Tier 3 Perform. OK? No Yes FEM Apply Results to other similar Structures Develop Retrofit Recommendation PS15-06 TM4 Appendix C 428 Orange County Sanitation District Structural Evaluation Approach - Liquid Containing Structures •Additional Structures w/ Liquefaction 24 •Tier 1 Modified •Compare loading and configuration to similar exemplar Tier 3 •Make assessment of performance based on Tier 3 •Tier 2 Modified •Confirm sufficiently dissimilar from exemplar Tier 3 •Perform simplified calculations that serve as basis of comparison to exemplar Tier 3 analysis Liquid Containing Structures Data Forms ASCE 41-13 Tier 1 Modified Similar Config to Tier 3? No ASCE 41-13 Tier 2 Modified Yes Perform. OK? No Yes Develop Retrofit Recommendation Evaluation Complete Perform. OK? No Develop Retrofit Recommendation Evaluation Complete PS15-06 TM4 Appendix C 429 Orange County Sanitation District Example Structure at Plant 1 Digester 16 25 PS15-06 TM4 Appendix C 430 Orange County Sanitation District 26 1111 1212 1313 1414 1515 1616 66 77 88 99 1010 55 PS15-06 TM4 Appendix C 431 Orange County Sanitation District 27 PS15-06 TM4 Appendix C 432 Orange County Sanitation District Foundation Plan 28 Diameter = 110 ft PS15-06 TM4 Appendix C 433 Orange County Sanitation District Base Slab 29 Historic construction photo from OCSD digester PS15-06 TM4 Appendix C 434 Orange County Sanitation District Cross-Section 30 Digester 7 interior view PS15-06 TM4 Appendix C 435 Orange County Sanitation District Ground Shaking Hazard 31 0.00 0.25 0.50 0.75 1.00 1.25 1.50 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Sp e c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (seconds) ASCE 41‐13 Horizontal Response Spectra ‐ OCSD Plant 1 ‐ Site Class D BSE‐2E (5%/50 yrs) BSE‐1E (20%/50 yrs) PS15-06 TM4 Appendix C 436 Orange County Sanitation District 32 Plant 1 Digester 16 Settlement Note: Horizontal not to scale Settlement (inches) Idealized Soil Profile Historic High Typical Plan View with Representative CPTs and Borings PS15-06 TM4 Appendix C 437 Orange County Sanitation District 33 Santa Ana River H = 10 ft Near Distance = 41 ft Far Distance = 155 ft Plant 1 Digester 16 Lateral Spread Note: Horizontal not to scale Far Lateral Spread (inches)Near Lateral Spread (inches) Idealized Soil Profile WE PS15-06 TM4 Appendix C 438 Orange County Sanitation District • ASCE 41-13 • ACI 350.3 Approach 34 Water bearing structures subjected to liquefaction‐induced PGD are non typical and require detailed assessment such as Tier 3 PS15-06 TM4 Appendix C 439 Orange County Sanitation District •Develop Finite Element Model using ANSYS •Compute impulsive and convective masses as per ACI 350.3 •Analyze the structure for ground shaking (response spectrum) and liquefaction‐induced PGD (assume range of boundary conditions) •Fixed base (for baseline reference only) •Flexible base •Explicit modeling of pile foundation Approach 35 PS15-06 TM4 Appendix C 440 Orange County Sanitation District Approach 36 0.00 0.25 0.50 0.75 1.00 1.25 1.50 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Spe c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (seconds) Ground Shaking Permanent Ground Deformation PS15-06 TM4 Appendix C 441 Orange County Sanitation District Finite Element Model 37 PS15-06 TM4 Appendix C 442 Orange County Sanitation District ACI 350.3 Loading 38 Impulsive mass 5% Damping Convective mass (1% Damping) Rigid PS15-06 TM4 Appendix C 443 Orange County Sanitation District Finite Element Model 39 Impulsive masses Soil springs (4 feet c/c) PS15-06 TM4 Appendix C 444 Orange County Sanitation District Finite Element Model 40 Convective masses PS15-06 TM4 Appendix C 445 Orange County Sanitation District Mode Shapes – Mode 1; Sloshing 41 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 446 Orange County Sanitation District Mode Shapes – Mode 2; Sloshing 42 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 447 Orange County Sanitation District Mode Shapes – Mode 3 43 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 448 Orange County Sanitation District Mode Shapes – Mode 4 44 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 449 Orange County Sanitation District Mode Shapes – Mode 6 45 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 450 Orange County Sanitation District Mode Shapes – Mode 7 46 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 451 Orange County Sanitation District Bending Moment (kip-in/in) 47 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 452 Orange County Sanitation District In-Plane Forces (kip/in) 48 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 453 Orange County Sanitation District Bending Moment in Base Cone 49 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 454 Orange County Sanitation District Membrane Forces in Base Cone 50 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 455 Orange County Sanitation District 51 In-Plane Forces in Compression Ring Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 456 Orange County Sanitation District 52 Preliminary Work‐in‐Progress Dome-to-Wall Connection PS15-06 TM4 Appendix C 457 Orange County Sanitation District Membrane Forces in the Dome 53 Preliminary Work‐in‐Progress PS15-06 TM4 Appendix C 458 Orange County Sanitation District Lateral Spread PGD 54 PS15-06 TM4 Appendix C 459 Orange County Sanitation District Bending Moment in Piles 55 PS15-06 TM4 Appendix C 460 Orange County Sanitation District Axial Force in Piles 56 PS15-06 TM4 Appendix C 461 Orange County Sanitation District Demand-to-Capacity Ratios Superstructure 57 DemandCapacity DemandCapacity DemandCapacity DemandCapacity Dome 0.9 1.4 0.1 1.4 0.1 3.9 0.2 3.9 0.67 2.5 2.0 ‐ 3.25 Dome to Wall Connection 2.9 2.8 0.0 2.8 0.9 10.9 7.0 12.3 1.12 2.5 2.0 ‐ 3.25 Compression Ring 9.4 15.7 0.0 2.8 2.0 30.4 7.3 31.8 0.67 2.5 2.0 ‐ 3.25 Wall Upper Third 9.6 27.4 0.0 8.6 1.6 312.7 6.3 77.5 0.35 2.5 2.0 ‐ 3.25 Wall Middle Third 11.7 45.7 0.1 8.6 6.7 521.2 35.3 77.5 0.47 2.5 2.0 ‐ 3.25 Wall Bottom Third 10.8 34.3 0.6 22.9 7.8 390.9 42.7 249.2 0.33 2.5 2.0 ‐ 3.25 Base Cone Slab 9.1 7.9 7.9 10.8 36.8 47.0 39.7 101.5 1.92 2.5 2.0 ‐ 3.25 Max Pile Force: 219 kips Punching Shear Capacity of Mat: 542 kips BSE‐2E N11 N22 M11 M22 DCR ASCE 41‐13 Life Safety m‐factor ACI‐350.3 R‐factor DemandCapacity DemandCapacity DemandCapacity DemandCapacity Dome 0.6 1.4 0.0 1.4 0.1 3.9 0.2 3.9 0.45 2.0 1.6 ‐ 2.6 Dome to Wall Connection 2.2 2.8 0.0 2.8 0.7 10.9 5.6 12.3 0.84 2.0 1.6 ‐ 2.6 Compression Ring 7.1 15.7 0.0 2.8 1.5 30.4 5.8 31.8 0.50 2.0 1.6 ‐ 2.6 Wall Upper Third 7.4 27.4 0.0 8.6 1.1 312.7 4.3 77.5 0.27 2.0 1.6 ‐ 2.6 Wall Middle Third 9.1 45.7 0.0 8.6 5.0 521.2 26.9 77.5 0.35 2.0 1.6 ‐ 2.6 Wall Bottom Third 8.5 34.3 0.0 22.9 5.7 390.9 31.7 249.2 0.26 2.0 1.6 ‐ 2.6 Base Cone Slab 6.8 7.9 5.8 10.8 28.0 47.0 30.7 101.5 1.45 2.0 1.6 ‐ 2.6 Max Pile Force: 180 kips Punching Shear Capacity of Mat: 542 kips BSE‐1E N11 N22 M11 M22 DCR ASCE 41‐13 Immediate Occupancy m‐factor ACI‐350.3 R‐factor (I = 1.25) PS15-06 TM4 Appendix C 462 Orange County Sanitation District Demand-to-Capacity Ratios - Piles 58 Load or Load Combination Maximum DCR* ASCE 41‐13 m‐factors** Best Estimate Lateral Spread Displacements 1.34 Upper Bound Lateral Spread Displacements 1.69 BSE‐2E Ground Shaking 2.42 BSE‐1E Ground Shaking 1.54 SRSS of Best Estimate Lateral Spread & BSE‐2E 2.0 ‐ 2.63 2.5 (LS) SRSS of Best Estimate Lateral Spread & BSE‐1E 1.5 ‐ 1.85 2.0 (IO) SRSS of Upper Bound Lateral Spread & BSE‐2E 2.19 ‐ 2.77 2.5 (LS) SRSS of Upper Bound Lateral Spread & BSE‐1E 1.79 ‐ 2.05 2.0 (IO) *Function of assumptions regarding directional combination of ground motion input; lower bound values for ASCE 41‐13 ** m‐factors based on ASCE 41‐13 Table 10‐9 for reinforced concrete columns; higher m‐factors for piles could be justified (ref: California Department of Transportation, 2017, Memo to Designers 20‐15, Lateral Spreading Analysis For New and Existing Bridges PS15-06 TM4 Appendix C 463 Orange County Sanitation District Example Structure at Plant 2 59 PS15-06 TM4 Appendix C 464 Orange County Sanitation District PEPS/MAC - Background 60 •Originally constructed under P2‐23‐6 in 1977 •Seismic retrofit work under P2‐53‐3 in 1994 •Single story w/ basement •170’ x 60’ x 50’ tall (16’ bg/34’ ag) •CIP concrete building w/ CIP conc roof (Class C2) •Supported on 2’‐0” thick concrete mat slab •Basement ties into 12 kV Distribution Center B and Headman Tunnel •1” diameter soil anchors w/ 33‐ft bonded length PS15-06 TM4 Appendix C 465 Orange County Sanitation District PEPS/MAC - Background 61 PS15-06 TM4 Appendix C 466 Orange County Sanitation District PEPS/MAC - Background 62 PS15-06 TM4 Appendix C 467 Orange County Sanitation District PEPS/MAC - Background 63 PS15-06 TM4 Appendix C 468 Orange County Sanitation District PEPS/MAC - Background 64 PS15-06 TM4 Appendix C 469 Orange County Sanitation District PEPS/MAC - Background 65 PS15-06 TM4 Appendix C 470 Orange County Sanitation District PEPS/MAC – Record Drawings 66 PS15-06 TM4 Appendix C 471 Orange County Sanitation District PEPS/MAC – Record Drawings 67 Connecting basement PS15-06 TM4 Appendix C 472 Orange County Sanitation District PEPS/MAC – Record Drawings 68 PS15-06 TM4 Appendix C 473 Orange County Sanitation District PEPS/MAC – Record Drawings 69 12 kV Dist B PEPS/MAC PS15-06 TM4 Appendix C 474 Orange County Sanitation District 70 Plant 2 PEPS/MAC Settlement Note: Horizontal not to scale Far Lateral Spread (inches) Typical Historic High Plan View with Representative CPTs and Borings PS15-06 TM4 Appendix C 475 Orange County Sanitation District 71 Near Distance = 294 ft Far Distance = 479 ftPlant 2 PEPS/MAC Lateral Spread Note: Horizontal not to scale WE Santa Ana River H = 10 ft Far Lateral Spread (inches)Near Lateral Spread (inches) PS15-06 TM4 Appendix C 476 Orange County Sanitation District 72 Far Distance = 614 ftPlant 2 PEPS/MAC Lateral Spread Note: Horizontal not to scale NS Talbert Marsh H = 10 ft Near Distance = 294 ft Far Lateral Spread (inches)Near Lateral Spread (inches) PS15-06 TM4 Appendix C 477 Orange County Sanitation District PEPS/MAC – Seismic Evaluation Criteria 73 Facility Structure Class Structural Performance Level Non‐ structural Performance Level Seismic Hazard Level 2‐5 PEPS/MAC I S‐1 (Immediate Occupancy) 1‐B (Position Retention) BSE‐1E (20% / 50 years) PS15-06 TM4 Appendix C 478 Orange County Sanitation District PEPS/MAC – Tier 1 Findings 74 Issue # Description Reference Comments S1 VERTICAL IRREGULARITY: Several shear walls are discontinuous down to the mat foundation. ASCE 41‐13 Check per Tier 3 Seismic Analysis PS15-06 TM4 Appendix C 479 Orange County Sanitation District PEPS/MAC – Tier 1 Findings 75 Issue # Description Reference Comments S2 SHEAR STRESS CHECK: DCR = 1.12 in the N‐S Direction ASCE 41‐13 Check per Tier 3 Seismic Analysis PS15-06 TM4 Appendix C 480 Orange County Sanitation District PEPS/MAC – Tier 1 Findings 76 Issue # Description Reference Comments S3 OPENINGS AT SHEAR WALLS: Diaphragm opening at roof > 15% of the wall length (60%). ASCE 41‐13 Check per Tier 3 Seismic Analysis 33’ PS15-06 TM4 Appendix C 481 Orange County Sanitation District PEPS/MAC – Tier 3 77 •3D FEM w/ flexible base •Evaluations 1. Response Spectrum Analysis (RSA) 2. Ground Deformation Analysis (GDA) 3. Combine RSA + GDA 4. Lateral Stability Check 5. Uplift Check PS15-06 TM4 Appendix C 482 Orange County Sanitation District PEPS/MAC – FEM Model 78 PS15-06 TM4 Appendix C 483 Orange County Sanitation District PEPS/MAC – FEM Model 79 PS15-06 TM4 Appendix C 484 Orange County Sanitation District PEPS/MAC – Soil Springs 80 •3 Soil Properties to Model •Vertical Bearing •Lateral Bearing (passive) •Base Friction •Bi‐linear •Linear elastic, perfectly plastic PS15-06 TM4 Appendix C 485 Orange County Sanitation District PEPS/MAC – Soil Springs 81 •Use upper bound stiffness for RSA •Use lower bound stiffness for GDA PS15-06 TM4 Appendix C 486 Orange County Sanitation District PEPS/MAC – Response Spectrum Analysis 82 •Model foundation flexibility (non‐liquefied) •Loads included: •BSE‐1E response spectra •Dead Load •Active soil loads (lateral) •Seismic soil loads •Groundwater pressures PS15-06 TM4 Appendix C 487 Orange County Sanitation District PEPS/MAC – Ground Deformation Analysis 83 •Model foundation flexibility (liquefied) •Loads/actions included: •Additional active soil pressures due to liquefaction •Dead Load •Differential settlement patterns •Linear •Bi‐linear •Other (will depend on building type) PS15-06 TM4 Appendix C 488 Orange County Sanitation District PEPS/MAC – Ground Deformation Analysis 84 •Linear pattern •Bi‐linear pattern Building Length/Width 3” 6” 6” 3” PS15-06 TM4 Appendix C 489 Orange County Sanitation District PEPS/MAC – Ground Deformation Analysis 85 •Bi‐linear pattern 0”3”0” 3”0”0” 1.5” 1.5”1.5” 1.5” PS15-06 TM4 Appendix C 490 Orange County Sanitation District PEPS/MAC – Tier 3 RSA + GDA 86 •Combine results using SRSS •Check component strength/ductility against ASCE 41‐13 Acceptance Criteria •Calculate Tier 3 DCR’s for Tier 1 “NC” items •Roof diaphragm shear •Concrete shear in shear walls •Concrete columns below discontinuous shear walls PS15-06 TM4 Appendix C 491 Orange County Sanitation District PEPS/MAC – Tier 3 GDA Adaption to Similar Structures 87 •Use results to judge performance of similar structures •Review ground deformation estimates for similar structures •Using same PEPS/MAC model, run analyses as required for: •Increased and/or decreased magnitudes of settlement •Perform independent lateral stability check for unique conditions •Limitations: •Not applicable for verifying Tier 1 structural deficiencies PS15-06 TM4 Appendix C 492 Orange County Sanitation District PEPS/MAC – Lateral Stability Check 88 •Challenges •How does differential spread occur? •Does the soil fracture? Where? In front, below, or behind? •Can the spread “pull” apart a structure? 10”5” PS15-06 TM4 Appendix C 493 Orange County Sanitation District PEPS/MAC – Lateral Stability Check 89 •Limit‐state checks •Passive pressure on basement walls •Any weak links in the foundation system •Expansion joints •Reduced slab sections •Reduced foundation width •Adjacent structures PS15-06 TM4 Appendix C 494 Orange County Sanitation District PEPS/MAC – Lateral Stability Check 90 •Basement Wall @ Grid Line 10 •Negative bending: DCR = 3.5 •Positive bending: DCR = X.X •Shear: DCR = 0.75 Passive earth pressure PS15-06 TM4 Appendix C 495 Orange County Sanitation District PEPS/MAC – Lateral Stability Check 91 •Foundation Wall @ Grid Line 1 Passive earth pressure PS15-06 TM4 Appendix C 496 Orange County Sanitation District PEPS/MAC – Lateral Stability Check 92 •Adjacent tunnel w/ expansion joints PS15-06 TM4 Appendix C 497 Orange County Sanitation District PEPS/MAC – Lateral Stability Check 93 •Adjacent tunnel PS15-06 TM4 Appendix C 498 Orange County Sanitation District PEPS/MAC – Uplift Check 94 •Check Buoyant Uplift •Reduced soil anchor capacity due to liquefaction •Increased buoyant uplift forces due to liquefied soil PS15-06 TM4 Appendix C 499 Orange County Sanitation District Path Forward for PS15-06 Structures 95 PS15-06 TM4 Appendix C 500 Orange County Sanitation District Discussion Discussion 96 PS15-06 TM4 Appendix C 501 \Mtg Minutes - OCSD 7-10-18 MEETING MINUTES SUBJECT: PS15-06 Technical Exchange Meeting (TEM) #2 DATE: Tuesday July 10, 2018 TIME: 9:00 a.m. PST LOCATION: OCSD Administration Building, Conference Room A MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering InfraTerra – Ahmed Nisar, Nick Doumbalski OCSD – Don Cutler, Mike Lahlou Jacobs – Elias Mageaes (Phone), Kirk Warnock (Phone), Jeong Yang (Phone) 1. Introduction/Safety Moment 2. Meeting Objectives Conkle described the objectives of the meeting as outlined on the attached slides. 3. Review of Structural Evaluation Process Conkle described outlined the structural evaluation process as described during the previous TEM. 4. Review of Geotechnical Site Conditions Hunt provided a summary of Geotechnical site conditions for the Digesters, Secondary Clarifiers, and City Water Pump Station as described on the attached slides. Discussions items during this section of the discussion included: PS15-06 TM4 Appendix C 502 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 2 ❖ There was discussion of the datum used to assess historic high-water depth. The topographic information being used has been provided by OCSD and uses the plant datum. This is different from the USGS datum per Don Cutler. ▪ Geosyntec acknowledges the difference between the USGS datum and plant datum. After discussion it was agreed that historic high likely represented an overly conservative basis for the evaluations relative to the typical water levels which are proposed for evaluations. ❖ Lahlou: Have we got any groundwater data from OCWD? ➢ Geosyntec responded that this request is still in progress and the elevations from the information received will be compared to those established based on the site-specific investigations. Geosyntec will prepare a discussion/justification for the groundwater elevations used in the evaluation. ❖ Lahlou: Is there QA/QC that is done on the CPTs to check if they include erroneous data? ➢ Hunt responded: We have used engineering judgment to identify outliers and have excluded them from the development of the settlement estimates. Our calculations have been thoroughly QC’d. ❖ Cutler: How is subgrade preparation work/effect of installation of piles below structures accounted for? The CPTs are advanced outside of structure footprints ➢ Hunt: This may be a minor source of conservatism. We will discuss this consideration in our report. ❖ Mageaes: Is the river lined at that location and normally dry, would that factor into the geotechnical conditions observed? ➢ Hunt/Nisar: There is a channel lining. The lining does not have the structural strength to resist moving soil to the free face. ➢ Conkle: While the river is generally dry, the free face for lateral spreading was taken down to the bottom of the channel and lateral spreading may occur at depths below the bottom of the channel. PS15-06 TM4 Appendix C 503 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 3 ❖ Lahlou: OCSD was expecting that Secondary Clarifiers at plant 2 would be the worst case as far as liquefaction/lateral spread. It appears that all 3 exemplars structures discussed today have liquefaction/lateral spread issues. ➢ Hunt: Yes, both plants have liquefiable soils. The geologic depositional environment is the same at both. ❖ Doumbalski provided a discussion of the evaluations for the Digesters at Plant 1. He noted that the pile capacities are about 100 kips. ❖ Hunt described the process for development of the geotechnical capacity of the piles. Assuming about 10% of frictional resistance at piles when liquefied. Installation effect of the pile would densify soils around piles somewhat. When calculating the shaft resistance, an effective diameter was used. In general, pile supported structures perform very well axially in earthquakes. We do not see gross sinking into the ground during earthquakes w/ liquefaction. We are accounting for these observations in the development of capacities. Lateral spread was not reduced to account for the presence of the piles. ❖ Warnock: Did you consider P-delta effect on concrete piles? ➢ Ahmed: Structural analysis included P-delta effect. Values on the chart are the geotechnical ultimate capacities (slide 26), which include the tip and side resistance. ❖ Mageaes: How do you determine soil consolidation below structures? Structures especially full of liquid may tend to consolidate soils. ➢ Hunt: Consolidation would have more of an effect on clays than the sandy soils we have at the site. We recommend not attempting to include this effect in a planning level study. ❖ Cutler: We do not want to be overly conservative in our approach. I believe based on our discussion that we are meeting that mark. ❖ Hunt provided a discussion of the differential settlement patterns assumed. There are lots of closely spaced CPTs at Plant 2. Four groups of these CPT were selected to look variability of closely space CPTs. A standard pattern with a reduction with a differential settlement of 40% of the total at 60 foot spacing . Structural engineers can then move that pattern around the structure to evaluate impact of differential settlement. ➢ Cutler: I understand we are just trying to look at how settlement might vary across the site, not trying to capture a cyclical response. PS15-06 TM4 Appendix C 504 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 4 ➢ Ahmed: It is not cyclical; the idea is that we are trying to capture a variable response. ➢ Lahlou: Is one of the grouping representative of native soils? ➢ Hunt: All were between structures and likely less effected by subgrade preparation at structures. ➢ Warnock: We understand this is a tool. I don’t have a problem with what they have done. 5. Plant 1 – Digesters – Progress Update ❖ Nisar presented a description of the progress on the evaluation of the digesters. ❖ Nisar: We developed moment-curvature in the piles and looked at incremental displacements. Top of curve occurs at 24 inches, after which the moment capacity reduces, but can go further. Dark red or dark blue are plastic hinges developing (Slide 53). Piles do develop hinges, but does not mean catastrophic failure and can still maintain structure loads. Piles have higher shear capacity than bending capacity, so elements are ductile. Failure is governed by ductile behavior. Modeled moment curvature using Pile v2.0. ❖ Lahlou: What about the base connection to the wall? ▪ Doumbalski: We checked the capacity of the wall. ▪ Nisar: Walls have relatively low DCR’s for ground shaking. The above ground responds to ground shaking and below ground structure responds to ground deformation. We start to see some limits on pile capacity at 24 inches. Even at 24 inches, not all piles have issues, just some of them. ▪ Warnock: Per ASCE 41-13, what would you like to have? ▪ Doumbalski: Limiting deformation to 12-inchs would help limit damage to any piles, since hinges start to form at 12 inches. PS15-06 TM4 Appendix C 505 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 5 ▪ Nisar: Cracking of the base slab could be treated as something we can live with. It is not a catastrophic failure. The main thing we are concerned with is the piles at the digesters. ▪ Doering: We are using these findings to give us insight to behavior at other pile- supported structures. ▪ Doumbalski: The displacement of the soil due to lateral spreading is driving the demand on the piles as opposed to the lateral load from the digester. ▪ Nisar: We are modeling the piles with full non-linear analysis. ▪ Warnock: For the moment-curvature analysis, do you know the reinforcement of the piles? • Doumbalski: Yes, we have that. It is on the drawings. ❖ Hunt: Ground improvement or a heavily reinforced sub-grade wall between the Digesters and the river can limit lateral spread displacement below 12 inches. ➢ Mageaes: You have 2 rows of digesters? How would that apply to the digesters away from the river? ➢ Hunt: Deformations at 2nd row are smaller about 14 inches. ➢ Doumbalski: It is possible that the 2nd row of digesters could be OK without mitigation. ❖ Lahlou: The road between digester and river is congested with utilities. Are you considering structural mitigations in addition to ground improvement? ➢ Ahmed: While we have not explored a perimeter pile mitigation yet. I think it will be challenging to make this work. ▪ Conkle: That may create differential settlement issues. ➢ Conkle: At this phase we are looking at the structural performance without mitigation in place. The next phase would be to, in Task 4, consider the mitigations in place to determine which is the best approach. PS15-06 TM4 Appendix C 506 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 6 ➢ Ahmed: One approach might be that without mitigation the first row would be sacrificial. If you do subject front row to high deformation, digesters will not topple, ▪ Cutler: That would be a management decision on our end. ▪ Doumbalski: The bottom cone slab will crack given these deformation ▪ Options to mitigate this cracking including post event repairs were discussed. ➢ Conkle: Hinging of piles is a real potential and would have to be addressed with ground improvement. What is the constraint at the front row as far as ground improvement? ▪ Cutler: There is process piping, 12 kV distribution along that access road. Feasibility of ground improvement may be low. ➢ Elias: Do the digester piles have pile caps? ▪ Doumbalski: There is thickening at the mat. ➢ Mageaes: So you have mirrored this in the model? ▪ Doumbalski: Yes, these are thickened rings. Rebar from the piles are anchored into the mat, so there is a rigid connection. ➢ Warnock: Were group effects included when the pile capacities were figured? ▪ Hunt: No, these are about 6 feet apart, so no reduction was made. ➢ Warnock: What is your opinion on fault rupture mitigation? ➢ Hunt: There is no fault rupture hazard at Plant 1. This concern is at Plant 2. The available information there shows that at the 975-year return period, the probability of fault displacement is very low. Fault rupture need not be assessed for return period less than 1400 years. Based on this information we do not think it is appropriate to apply fault rupture hazard to the existing structure in this study. We will document this position in our report. ➢ Mageaes: Potential cracking of the cone? ▪ Doumbalski: Yes. ➢ Mageaes: Is that quantifiable? What more can you tell us? PS15-06 TM4 Appendix C 507 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 7 ▪ Doumbalski: Middle of the cone rises relative to the outer portion given pile performance, so the cone is stretching, creating membrane stresses that will potentially crack the slab. ▪ Nisar: Won’t reach a catastrophic failure. ➢ Cutler: It seems unusual that the piles are not toed into the same stratum. I am guessing that when we constructed digesters, we hammered piles down to refusal and cut off to the appropriate elevation. Ahmed: The drawings show the pile length is set. No refusal number or bearing strata is provided. 6. Plant 1 - City Water Pump Station – Progress Update ❖ Doering provided a description of the City Water Pump Station and the results of structural evaluations as described on the attached presentation. A preliminary list of structural mitigation items was presented. ➢ Tie slab to wall/stem wall ➢ Upgrade beam connections to roof diaphragm (4 locations) ➢ Reinforce overstressed wall pier @ south wall ➢ Supplement wall with horizontal girts ❖ While subject to liquefaction and lateral spreading, performance may be acceptable slab is adequately tied to walls allowing structure to move as a unit. ❖ Lahlou: Was this structure identified as requiring a retrofit in the Dame and Moore Report? ➢ Doering: The structure was built in 1989 and the Dames and Moore report in 1994 didn’t identify required retrofit at this structure. ❖ Lahlou: Is there a way to present a combined demand capacity ratio (DCR) for the structure? ➢ Doering: No, the DCRs need to apply to particular structural elements. ❖ Warnock: In the past it was common to isolate the slab from the wall for shrinkage reasons. ➢ The group agreed that current design practice and an appropriate retrofit would be to tie the slab to the walls. 7. Plant 2 - Secondary Clarifiers A-L – Progress Update ❖ Nisar and Doumbalski provided a description of the Secondary Clarifiers at Plant 2 and the results of structural evaluations based on ground shaking the geotechnical conditions PS15-06 TM4 Appendix C 508 PS15-06 Technical Exchange Meeting #2 July 10, 2018 Page 8 identified. While the structure performs well relative to ground shaking; lateral spreading and differential settlement produce separations between portions of the structure which would produce a loss of function after the design seismic event. This separation causes loss of support of mechanical equipment which bridge the various structures. ❖ The performance and loss of function indicates that either ground improvement or a post earthquake repair may be appropriate mitigation options. ❖ Cutler: The performance presented sounds catastrophic. Given the age of the structure it may have little remaining useful life. This will need to be considered in the ultimate retrofit/replace decision. ➢ Conkle: Understood. The team will present feasible mitigation alternatives including ground improvement which the District can ultimately weight against a replacement decision during the TM4 phase. 8. Discussion ❖ Warnock: Speaking generally about the day’s meeting. “This was a very thorough and very professional presentation”. Action Items: • Geosyntec to prepare meeting minutes. • TM-1 will be issued addressing the comments received thus far. Additional detail regarding approach, including items discussed in this meeting, will be documented in TM-3. • Further discussion is needed on how we choose deformation-controlled vs force- controlled for structural checks. This discussion will happen in meetings specific to the evaluation of each structure. ***** Attachments • PowerPoint slides from Presentation 7-10-18 PS15-06 TM4 Appendix C 509 Orange County Sanitation District Orange County Sanitation District TECHNICAL EXCHANGE MEETING #2 SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 JULY 10, 2018 PRESENTED BY: Geosyntec Team PS15-06 TM4 Appendix C 510 Orange County Sanitation District Agenda •Introduction/Safety Moment •Meeting Objectives •Review of Structural Evaluation Process •Review of Geotechnical Site Conditions •Plant 1 –Digesters –Progress Update •Plant 1 -City Water Pump Station –Progress Update •Plant 2 -Secondary Clarifiers A-L –Progress Update •Discussion 2 PS15-06 TM4 Appendix C 511 Orange County Sanitation District Safety Moment –Dehydration How does our body lose water? 1) Respiration: 1-2 liters of water 2) Perspiration: 1-2 liters per day. During heavy exertion, we can lose 1-3 liters of water per hour, which can easily amount to 8-10 liters of fluid over an afternoon of exercise. 3) Urination: 1-2 liters of water are lost daily to urination. 3 PS15-06 TM4 Appendix C 512 Orange County Sanitation District Safety Moment –Dehydration Symptoms of Dehydration 1) Mild to Moderate: a. Dry or “gooey” mouth b. Headache, red face, elevated body temperature c. Thirst, possible loss of appetite d. Decreased urine volume and/or dark urine, constipation e. Unexplained tiredness, loss of endurance, rapid fatigue f. Dizziness when standing 2) Severe (the above possibilities, intensified, plus): a. Irritability, fussiness or confusion b. Dry skin and mucous membranes; may not sweat c. Little or no urination, or dark yellow or amber in color d. Sunken eyes e. Loss of skin elasticity; Doesn’t bounce back when compressed f. Low blood pressure g. Rapid heartbeat h. Fever i. Tingling in the limbs j. Delirium or unconsciousness . 4 PS15-06 TM4 Appendix C 513 Orange County Sanitation District Safety Moment –Dehydration Tips for Preventing Dehydration 1) DRINK LOTS OF WATER. 2) Drink before you are thirsty. 3) Always have fluids within reach, especially during exercise or in warm weather. 4) Watch your urine. Urination every 3-5 hours and light-colored or clear urine are good signs. 6) Dress for the heat and reduce activity; reserve strenuous work for the cool parts of the day 7) Give your body time to condition itself to the heat before big exertion. This may take a while (days and weeks) 8) Get enough sleep . 5 PS15-06 TM4 Appendix C 514 Orange County Sanitation District Meeting Objectives •Provide “in progress” update on Task 3 •Present initial findings and observations for three exemplar groups •Get feedback from OCSD on these findings to direct further efforts •Facilitate review of Upcoming Deliverables 6 PS15-06 TM4 Appendix C 515 Orange County Sanitation District Review of Structural Evaluation Process •Exemplar Buildings w/ Liquefaction 7 Exemplar Building Structures ASCE 41-13 Tier 3 Perform. OK? No Yes FEM Apply Results to other similar Building Structures Develop Retrofit Recommendation PS15-06 TM4 Appendix C 516 Orange County Sanitation District Review of Structural Evaluation Process •Additional Buildings w/ Liquefaction 8 Building Structures ASCE 41-13 Tier 1 ASCE 41-13 Tier 1 Modified Similar Config to Tier 3? No ASCE 41-13 Tier 2 Modified Yes Perform. OK? No Yes Develop Retrofit Recommendation Evaluation Complete •Tier 1 Modified •Compare loading and configuration to similar exemplar Tier 3 •Make assessment of performance based on Tier 3 •Tier 2 Modified •Confirm sufficiently dissimilar from exemplar Tier 3 •Perform simplified calculations that serve as basis of comparison to exemplar Tier 3 analysis Perform. OK? No Develop Retrofit Recommendation Evaluation Complete PS15-06 TM4 Appendix C 517 Orange County Sanitation District Review of Structural Evaluation Process Structural Groups •Digesters •Secondary Clarifiers •Gas Holders •Surge Towers •Aeration Basins •DAFTs •Buildings -Mat Foundation with Basement •Buildings -Deep Foundations with Basement •Central Power Generation Building/OOBS •Buried Boxes •Buildings -Shallow Foundation 9 PS15-06 TM4 Appendix C 518 Orange County Sanitation District Review of Structural Evaluation Process Structural Groups •Digesters –Digester 16 •Secondary Clarifiers –A-L •Gas Holders •Surge Towers •Aeration Basins •DAFTs •Buildings -Mat Foundation with Basement •Buildings -Deep Foundations with Basement •Central Power Generation Building/OOBS •Buried Boxes •Buildings -Shallow Foundation –City Water Pump Station 10 PS15-06 TM4 Appendix C 519 Orange County Sanitation District •Investigation Locations and Target Structures •Groundwater Levels •Idealized Soil profiles •Settlement and Lateral Spread Potential •Inputs to Structural Analysis •Deep Foundations •Shallow Foundations Geotechnical Site Conditions 11 PS15-06 TM4 Appendix C 520 Orange County Sanitation District Investigation Locations and Target Structures 12 •Plant 1 •Digester 16 / Front Row •City Water Pump Station PS15-06 TM4 Appendix C 521 Orange County Sanitation District Investigation Locations and Target Structures 13 •Plant 2 •Secondary Clarifiers PS15-06 TM4 Appendix C 522 Orange County Sanitation District •Consideration of Historic High (HH) water level •Based on maps of depth to groundwater from CA Geological Survey (Seismic Hazard Zone Report) •Often used for new design work •Conservative for assessment of existing performance if recent GW depth is lower •Assessment of “Analysis Water Level (AWL)” •Establish a suitably conservative groundwater elevation for analysis •Based on more recent site-specific information (boring logs and well data) •More appropriate for a planning study on existing structures •In all cases lower than equivalent HH level Groundwater Level Approach 14 Historic High (HH) Water Depth Analysis Water Level (AWL) Plant 1 5 ft-bgs +16 ft elev Plant 2 3 ft-bgs +2 ft elev PS15-06 TM4 Appendix C 523 Orange County Sanitation District Idealized Soil Profile –Digester 16 15 PS15-06 TM4 Appendix C 524 Orange County Sanitation District Idealized Soil Profile –Digester 16 16 PS15-06 TM4 Appendix C 525 Orange County Sanitation District Liquefaction Displacements –Digester 16 17 Focus is on “best estimate” case, with consideration of effects of “upper estimate”. PS15-06 TM4 Appendix C 526 Orange County Sanitation District Idealized Soil Profile –City Water PS 18 PS15-06 TM4 Appendix C 527 Orange County Sanitation District Idealized Soil Profile –City Water PS 19 PS15-06 TM4 Appendix C 528 Orange County Sanitation District Displacements –City Water Pump Station 20 PS15-06 TM4 Appendix C 529 Orange County Sanitation District Idealized Soil Profile –Secondary Clarifiers 21 8 7 5 3 1 2 4 6 PS15-06 TM4 Appendix C 530 Orange County Sanitation District Idealized Soil Profile –Secondary Clarifiers 22 PS15-06 TM4 Appendix C 531 Orange County Sanitation District Displacements –Secondary Clarifiers 23 PS15-06 TM4 Appendix C 532 Orange County Sanitation District Displacements –Secondary Clarifiers 24 PS15-06 TM4 Appendix C 533 Orange County Sanitation District •Pile Capacity (unliquefied and liquefied) •P-Y Lateral Springs (unliquefied and liquefied) •T-Z Axial Shaft Springs (unliquefied) •Q-Z Axial Tip Springs (unliquefied) Soil Structure Interaction -Pile Foundations 25 PS15-06 TM4 Appendix C 534 Orange County Sanitation District Digester 16 Pile Capacity 26 A B C D E F G H •7 pile rings (A-G) + center piles (H) •12”x12” concrete piles •All 52 ft long, varying elevations •Deeper piles = higher capacity •Reduced capacity in liquefiable soils, but assumed some pile improvement effect PS15-06 TM4 Appendix C 535 Orange County Sanitation District 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 p ( l b s / i n ) y (in) Depth = 0.00 ft Depth = 4.00 ft Depth = 8.00 ft Depth = 12.00 ft Depth = 16.00 ft Depth = 20.00 ft Depth = 24.00 ft Depth = 28.00 ft Depth = 32.00 ft Depth = 36.00 ft Depth = 40.00 ft Depth = 44.00 ft Depth = 48.00 ft Depth = 52.00 ft •Unliquefied Digester 16 –P-Y Springs 27 “A” Ring Piles PS15-06 TM4 Appendix C 536 Orange County Sanitation District •Liquefied •P-multiplier of 0.1 in liquefied soil Digester 16 –P-Y Springs 28 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 p ( l b s / i n ) y (in) Depth = 0.00 ft Depth = 4.00 ft Depth = 8.00 ft Depth = 12.00 ft Depth = 16.00 ft Depth = 20.00 ft Depth = 24.00 ft Depth = 28.00 ft Depth = 32.00 ft Depth = 36.00 ft Depth = 40.00 ft Depth = 44.00 ft Depth = 48.00 ft Depth = 52.00 ft “A” Ring Piles PS15-06 TM4 Appendix C 537 Orange County Sanitation District 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 p ( l b s / i n ) y (in) Depth = 0.00 ft Depth = 4.00 ft Depth = 8.00 ft Depth = 12.00 ft Depth = 16.00 ft Depth = 20.00 ft Depth = 24.00 ft Depth = 28.00 ft Depth = 32.00 ft Depth = 36.00 ft Depth = 40.00 ft Depth = 44.00 ft Depth = 48.00 ft Depth = 52.00 ft •Unliquefied Digester 16 –P-Y Springs 29 “H” Center Piles PS15-06 TM4 Appendix C 538 Orange County Sanitation District 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 p ( l b s / i n ) y (in) Depth = 0.00 ft Depth = 4.00 ft Depth = 8.00 ft Depth = 12.00 ft Depth = 16.00 ft Depth = 20.00 ft Depth = 24.00 ft Depth = 28.00 ft Depth = 32.00 ft Depth = 36.00 ft Depth = 40.00 ft Depth = 44.00 ft Depth = 48.00 ft Depth = 52.00 ft •Liquefied •P-multiplier of 0.1 in liquefied soil Digester 16 –P-Y Springs 30 “H” Center Piles PS15-06 TM4 Appendix C 539 Orange County Sanitation District •Only unliquefied springs developed •Liquefied springs seldom analyzed as lateral effects tend to control for deep foundations in liquefied ground Digester 16 –T-Z and Q-Z Springs 31 “A” Ring Piles 0 5,000 10,000 15,000 20,000 25,000 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 Mo b i l i z e d S h e a r R e s i s t a n c e ( l b s ) Local Pile Displacement, z (in) Depth = 0.00 ft Depth = 4.00 ft Depth = 8.00 ft Depth = 12.00 ft Depth = 16.00 ft Depth = 20.00 ft Depth = 24.00 ft Depth = 28.00 ft Depth = 32.00 ft Depth = 36.00 ft Depth = 40.00 ft Depth = 44.00 ft Depth = 48.00 ft Depth = 52.00 ft 0 20 40 60 80 100 120 140 0.00 0.50 1.00 1.50 2.00 Mo b i l i z e d E n d B e a r i n g R e s i s t a n c e , Q (k i p s ) Axial Pile Tip Displacement, z (in.)PS15-06 TM4 Appendix C 540 Orange County Sanitation District •Anchor Capacity (liquefied and unliquefied) •Calculation similar to pile capacity (shaft resistance only) •Reduced capacity in liquefied soil •Lateral Earth Pressures •Not generally controlling for embedded structures •Not included for current 3 structures •Geotechnical Inputs to Soil Springs (unliquefied) •Liquefied condition seldom analyzed for bearing springs •Differential Settlement •Analysis of closely-spaced CPTs to evaluate potential variability Soil Structure Interaction –Shallow Fnds 32 PS15-06 TM4 Appendix C 541 Orange County Sanitation District •Following ASCE 41-13, Section 8.4.2.2 •Poisson’s Ratio •0.5 for saturated clay •0.25 for other soils •Initial Shear Modulus (ASCE 41-13, Eqn. 8-4) •Based on range of shear wave velocities measured during site investigation •(ASCE 41-13, Eqn. 8-4) Geotech Inputs to Soil Springs 33 (ft-bgs)(pcf)(ft/s)(ft/s)(psf)(psf) 1-4 City Water Pump Station Shallow Spread 3.25 120 500 800 900,000 2,400,000 0.25 1-29 Shop Building A Shallow Spread 0 120 500 800 900,000 2,400,000 0.25 2-5 PEPS & MAC Basement + 2' Mat w/ tie-down anchors 19 125 550 750 1,200,000 2,200,000 0.25 2-17 Central Power Generation Building Basement + 9' Mat 25 125 550 750 1,200,000 2,200,000 0.25 2-18 Aeration Basins A-H 1'-4" Mat w/ tie-down anchors 14.33 125 550 750 1,200,000 2,200,000 0.25 2-19 Gas Holder Ring Wall Footing 17.5 125 550 750 1,200,000 2,200,000 0.25 2-20 Secondary Clarifiers A-L 1'-3" Mat w/ tie-down anchors 12.75 125 550 750 1,200,000 2,200,000 0.25 2-22 DAFT D 1'-0" Mat 9.25 125 550 750 1,200,000 2,200,000 0.25 2-24 Surge Tower No. 2 2'-0" Mat 16 125 550 750 1,200,000 2,200,000 0.25 2-29 OOBS Basement + 9' Mat for main bldgThinner mat towards outfall at river 25 to 12(?)125 550 750 1,200,000 2,200,000 0.25 ID No. Upper Shear Wave Velocity, Vs Lower Stiffness, G0 Upper Stiffness, G0 Non-Piled Structure Name Lower Shear Wave Velocity, Vs Total Unit Weight, g Foundation Depth Foundation Type Poissons Ratio, n PS15-06 TM4 Appendix C 542 Orange County Sanitation District •Four groupings of closely-spaced CPTs at Plant 2 selected •Not intended for specific structures, but for assessment of variability across plant(s) Differential Settlement 34 PS15-06 TM4 Appendix C 543 Orange County Sanitation District 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 50 100 150 200 To t a l S e t t l e m e n t / M a x i m u m T o t a l S e t t l e m e n t i n Ea c h C P T S e r i e s ( % ) Distance Along CPT Cross-Section (ft) Southwest Northeast Northwest Southeast •Settlements calculated at each CPT •Total calculated settlement normalized by maximum group settlement •Resulted in 4 “patterns” of differential settlement from CPT variability Differential Settlement 35 PS15-06 TM4 Appendix C 544 Orange County Sanitation District 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 0 50 100 150 200 To t a l S e t t l e m e n t / M a x i m u m T o t a l S e t t l e m e n t i n Ea c h C P T S e r i e s ( % ) Distance Along CPT Cross-Section (ft) Southwest Northeast Northwest Southeast Sine Wave #3 - 40% in 60 feet •Fit sine wave through data to develop average “pattern” •Peak to Trough is 40% of max settlement at 60 feet distance •Other potential patterns (30% in 75 feet and 50% in 50 feet) to be considered qualitatively based on findings from average case Differential Settlement 36 PS15-06 TM4 Appendix C 545 Orange County Sanitation District Plant 1-Digesters Update 37 PS15-06 TM4 Appendix C 546 Orange County Sanitation District 38 11 12 13 14 15 16 6 7 8 9 10 5 PS15-06 TM4 Appendix C 547 Orange County Sanitation District Digester 16 -Structural Summary 39 PS15-06 TM4 Appendix C 548 Orange County Sanitation District Foundation Plan 40 Diameter = 110 ft PS15-06 TM4 Appendix C 549 Orange County Sanitation District Base Slab 41 Historic construction photo from OCSD digester PS15-06 TM4 Appendix C 550 Orange County Sanitation District Cross-Section 42 Digester 7 interior view PS15-06 TM4 Appendix C 551 Orange County Sanitation District •Evaluation Approach for Digesters •Tier 3 for Digester 16 •Tier 1 “Modified” for other structures based on the results of Tier 1 Digesters –Plant 1 43 Di g e s t e r Nu m b e r of p i l e s Sh e l l Di a m e t e r ( f t ) Ar e a p e r Pi l e (s f t ) Sh e l l Th i c k n e s s (i n ) Sh e l l He i g h t (f t ) Do m e Ra d i u s (f t ) Do m e Th i c k n e s (i n ) Di s t a n c e fo r m Ri v e r ( f t ) Do m e Re i n f o r c e m e n t Ra t i o Ve r t i c a l W a l l Re i n f o r c e m e n t Ra t i o Ho r i z o n t a l W a l l Re i n f o r c e m e n t Ra t i o Comparison to Digester 16 Digester 5 251 90 25 19 30.5 75 5 400 0.68% 0.32% 1.40% Smaller than D16, further from river Digester 6 251 90 25 22 30.5 Steel 1/4"500 N/A 0.32% 1.43% Smaller than D16, further from river, steel dome Digester 7 280 90 23 22 30.5 75 5 250 1.07% 0.57% 1.52% Smaller than D16, further from river Digester 8 280 90 23 22 30.5 75 5 300 0.93% 0.57% 1.44% Smaller than D16, further from river Digester 9 242 110 39 27 31.5 108.5 6 100 0.43% 0.27% 1.45'% Similar to D16, fewer piles Digester 10 242 110 39 27 31.5 108.5 6 100 0.43% 0.27% 1.45'% Similar to D16, fewer piles Digester 11 280 110 34 27 31.5 108.5 6 250 0.43% 0.48% 2.02% Identical to D16, further from river Digester 12 280 110 34 27 31.5 108.5 6 250 0.43% 0.48% 2.02% Identical to D16, further from river Digester 13 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Identical to D16 Digester 14 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Identical to D16 Digester 15 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Identical to D16 Digester 16 280 110 34 27 31.5 108.5 6 100 0.43% 0.48% 2.02% Exemplar PS15-06 TM4 Appendix C 552 Orange County Sanitation District Potential Failure Modes Description PFM1 Ground shaking (GS) -Failure of dome-wall connection PFM2 GS -Failure of dome PFM3 GS -Hoop stress failure in wall PFM4 GS -Out-of-plane bending/shear in wall PFM5 GS -Punching of mat PFM6 GS -Vertical failure of piles PFM7 GS -Bending/shear failure of piles PFM8 Liquefaction Setttlement -Punching of Mat by Piles PFM9 LIquefaction Settlement -Vertical loss of capacity of piles PFM10 Lateral Spreading -Bending/shear failure of piles PFM11 Liquefaction Settlement -Local Deformation of Foundation Cone Digester 16 –Potential Failure Modes 44 PS15-06 TM4 Appendix C 553 Orange County Sanitation District Approach 45 0.00 0.25 0.50 0.75 1.00 1.25 1.50 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 Spe c t r a l R e s p o n s e A c c e l e r a t i o n , S a ( g ) Period, T (seconds) ASCE 41-13 Horizontal Response Spectra -OCSD Plant 1 -Site Class D Ground Shaking Permanent Ground Deformation PS15-06 TM4 Appendix C 554 Orange County Sanitation District 46 Finite Element Model PS15-06 TM4 Appendix C 555 Orange County Sanitation District ACI 350.3 Loading 47 Impulsive mass 5% Damping Convective mass (1% Damping) Rigid PS15-06 TM4 Appendix C 556 Orange County Sanitation District Finite Element Model 48 Impulsive masses Soil springs (4 feet c/c) PS15-06 TM4 Appendix C 557 Orange County Sanitation District Finite Element Model 49 Convective masses PS15-06 TM4 Appendix C 558 Orange County Sanitation District Digester 16 –Structural Evaluations/Findings 50 Demand Capacity Demand Capacity Demand Capacity Demand Capacity DCR m-factor (IO) ASCE 41-13 m-factor (LS) ASCE 41-13 R-factor ACI- 350 Dome _MID 0.00 1.40 0.00 1.40 0.25 3.91 1.00 3.91 0.26 2.00 2.50 2.50 Dome to Wall 0.00 2.79 0.00 2.79 0.80 10.88 3.28 12.28 0.27 2.00 2.50 2.50 Compr Ring 0.00 15.73 0.00 2.79 0.68 30.41 1.88 31.81 0.06 2.00 2.50 2.00 Wall TOP 2.66 27.43 0.00 8.63 1.41 312.72 7.46 77.50 0.10 2.00 2.50 2.00 Wall MID 6.27 45.72 0.00 8.63 2.38 521.21 10.49 77.50 0.14 2.00 2.50 2.00 Wall BOT 8.00 34.29 0.00 22.86 6.02 390.91 36.85 249.17 0.25 2.00 2.50 2.00 *CONE 12.13 7.92 11.57 10.80 98.51 46.00 138.80 99.00 2.14 2.00 2.50 2.00 Max Pile Shear Force:107 kips Punching Shear Capacity of Mat:62 kips Demand Capacity Demand Capacity Demand Capacity Demand Capacity DCR m-factor (IO) ASCE 41-13 m-factor (LS) ASCE 41-13 R-factor ACI- 350 Dome _MID 0.00 1.40 0.00 1.40 0.35 3.91 1.27 3.91 0.33 2.00 2.50 2.50 Dome to Wall 0.00 2.79 0.00 2.79 1.10 10.88 4.42 12.28 0.36 2.00 2.50 2.50 Compr Ring 0.00 15.73 0.00 2.79 0.73 30.41 2.39 31.81 0.08 2.00 2.50 2.00 Wall TOP 3.70 27.43 0.00 8.63 1.89 312.72 10.47 77.50 0.14 2.00 2.50 2.00 Wall MID 7.85 45.72 0.00 8.63 3.55 521.21 18.62 77.50 0.24 2.00 2.50 2.00 Wall BOT 11.80 34.29 1.38 22.86 9.44 390.91 54.42 249.17 0.37 2.00 2.50 2.00 *CONE 15.00 7.92 13.93 10.80 107.77 46.00 150.49 99.00 2.34 2.00 2.50 2.00 Typical GW Best Estimate Displacements M22 PilesTypical GW Best Est. Dislacement + EQ N11 N22 M11 Piles Typical GW Best Est. Dislacement N11 N22 M11 M22 PS15-06 TM4 Appendix C 559 Orange County Sanitation District Moment Curvature (Roof-Dome) 51 >10 PS15-06 TM4 Appendix C 560 Orange County Sanitation District Moment Curvature (Wall to Dome Connection 52 >10 PS15-06 TM4 Appendix C 561 Orange County Sanitation District Moment Curvature (Piles) 53 PS15-06 TM4 Appendix C 562 Orange County Sanitation District Moment Curvature (Piles) 54 PS15-06 TM4 Appendix C 563 Orange County Sanitation District Moment Curvature (Piles) 55 PS15-06 TM4 Appendix C 564 Orange County Sanitation District •Option 1: Ground improvement to limit lateral spread •Construct ground improvement shear panels in roadway area east of Digesters •Design spacing and strength to limit failure surface behind the improved zone •Ground improvement methods: Auger soil mixing, cutter soil mixing, slurry wall method, jet grouting, … •Key ground improvement elements: •Large footprint •Must achieve high strength and/or large “replacement volume” •“Key” improvement below lateral spread zone (~ Elev. -10 feet) •Some localized settlement reduction impacts Digesters–Mitigation Concepts -PFM10 56 PS15-06 TM4 Appendix C 565 Orange County Sanitation District •Option 1: Ground improvement to limit lateral spread Digester 16 –Mitigation Concepts -PFM10 57 Santa Ana RiverDigester Ground Improvement Zone PS15-06 TM4 Appendix C 566 Orange County Sanitation District •Option 2: Subsurface retaining wall to limit lateral spread •Construct wall in roadway area east of digesters •Design wall to resist earth pressure from lateral spread without excessive deflection •Wall types: secant pile wall, cutter soil mix wall, … •Key wall elements •Significant depth (~100 ft), founded below liquefaction zone •Heavily reinforced to limit deflections Digesters –Mitigation Concepts -PFM10 58 PS15-06 TM4 Appendix C 567 Orange County Sanitation District Digesters –Hydraulic Flow Diagram 59 PS15-06 TM4 Appendix C 568 Orange County Sanitation District Plant 1 City Water PS -Background 60 •Originally constructed under P1-34-1 in 1989 •Single story @ grade •62’ x 40’ x 17’ tall •Reinforced masonry building w/ conc-topped steel deck diaphragm (Class RM1A) •Founded on shallow continuous spread footings •Adjacent to the Santa Ana River PS15-06 TM4 Appendix C 569 Orange County Sanitation District City Water PS -Background 61 PS15-06 TM4 Appendix C 570 Orange County Sanitation District City Water PS -Structural Summary 62 PS15-06 TM4 Appendix C 571 Orange County Sanitation District City Water PS -Background 63 PS15-06 TM4 Appendix C 572 Orange County Sanitation District City Water PS -Background 64 PS15-06 TM4 Appendix C 573 Orange County Sanitation District City Water PS -Background 65 PS15-06 TM4 Appendix C 574 Orange County Sanitation District City Water PS -Background 66 PS15-06 TM4 Appendix C 575 Orange County Sanitation District City Water PS –Record Drawings 67 PS15-06 TM4 Appendix C 576 Orange County Sanitation District City Water PS –Record Drawings 68 PS15-06 TM4 Appendix C 577 Orange County Sanitation District City Water PS –Seismic Evaluation Criteria 69 Facility Structure Class Structural Performance Level Non- structural Performance Level Seismic Hazard Level 1-4 City Water PS I S-1 (Immediate Occupancy) 1-B (Position Retention) BSE-1E (20% / 50 years) PS15-06 TM4 Appendix C 578 Orange County Sanitation District City Water PS –Seismic Evaluation Criteria 70 PS15-06 TM4 Appendix C 579 Orange County Sanitation District Potential Failure Modes Description PFM1 Ground shaking (GS) -In-plane shear failure in walls PFM2 GS -Out-of-plane bending/shear failure in walls PFM3 GS -Shear failure in roof diaphragm PFM3 GS -Wall anchorage failure at roof PFM4 Ground deformation (GD) -Liquefaction w/ differential settlement (PFM1 to PFM3 failures) PFM5 Ground deformation (GD) -Lateral spread of foundation (footing moves and causes building instability) PFM6 GS -Stability of Foundation PFM7 Ground shaking (GS) -In-plane shear failure in walls City Water Pump Sta.–PFMs 71 PS15-06 TM4 Appendix C 580 Orange County Sanitation District City Water PS –Tier 1 Findings 72 Issue #Description Reference Comments S1 TIES BETWEEN FOUNDATION ELEMENTS: Several shear walls are discontinuous down to the mat foundation. ASCE 41-13 Reduced capacity to resist lateral spread. PS15-06 TM4 Appendix C 581 Orange County Sanitation District City Water PS –Tier 1 Findings 73 Issue #Description Reference Comments S2 WALL ANCHORAGE: Anchorage force at the roof connection of the roof beam to the CMU wall does not meet the performance requirements. ASCE 41-13 Check per Tier 2 PS15-06 TM4 Appendix C 582 Orange County Sanitation District City Water PS –Tier 1 Findings 74 Issue #Description Reference Comments S3 REINFORCING STEEL: The spacing of the horizontal bars in the CMU walls is 48 inches. Insufficient horizontal reinforcement. ASCE 41-13 Check horizontal bending moments in the wall per Tier 3 analysis PS15-06 TM4 Appendix C 583 Orange County Sanitation District City Water PS –Tier 3 Exemplar 75 •3D FEM w/ flexible base •Evaluations 1.Ground Motion Response (GMR) 2.Ground Deformation Response (GDR) 3.Combine GMR + GDR 4.Lateral Stability Check 5.Exemplar Analyses 1.Increased ground deformation 2.Decreased ground deformation PS15-06 TM4 Appendix C 584 Orange County Sanitation District City Water PS –FEM Model 76 PS15-06 TM4 Appendix C 585 Orange County Sanitation District City Water PS –FEM Model 77 PS15-06 TM4 Appendix C 586 Orange County Sanitation District City Water PS –Soil Springs 78 •Soil Properties to Modeled •Vertical Bearing (z-direction) •Base Friction (x & y directions) •Bi-linear •Linear elastic, perfectly plastic PS15-06 TM4 Appendix C 587 Orange County Sanitation District City Water PS –Soil Springs 79 PS15-06 TM4 Appendix C 588 Orange County Sanitation District City Water PS –Ground Motion Response 80 •Model foundation flexibility (non-liquefied) •Loads included: •BSE-1E response spectra •Dead Load •Estimate demands on structural members •Focus on PFMs and deficiencies from Tier 1 PS15-06 TM4 Appendix C 589 Orange County Sanitation District City Water PS –Ground Motion Analysis 81 •In-plane Shear PS15-06 TM4 Appendix C 590 Orange County Sanitation District City Water PS –Ground Motion Analysis 82 •Out-of-plane Shear PS15-06 TM4 Appendix C 591 Orange County Sanitation District City Water PS –Ground Motion Analysis 83 •Out-of-plane Bending PS15-06 TM4 Appendix C 592 Orange County Sanitation District City Water PS –Ground Motion Analysis 84 •Tension in Wall PS15-06 TM4 Appendix C 593 Orange County Sanitation District City Water PS –GMR Preliminary Findings 85 Item Demand Capacity m-factor GMR DCR In-plane shear @ south pier 288 psi 99 psi 2.0 1.45 In-plane shear @ south wall 130 psi 99 psi 2.0 0.66 In-plane shear @ west wall 70 psi 99 psi 2.0 0.35 Out-of-plane shear 24.2 psi 95 psi N/A 0.26 Out-of-plane bending, Mx/My 2.5 k-ft / 1.0 k-ft 1.4 k-ft / 5.1 k-ft N/A 1.79 / 0.20 Tension in wall 150 psi 128 psi 2.0 0.65 PS15-06 TM4 Appendix C 594 Orange County Sanitation District City Water PS –Ground Deformation Response 86 •Model foundation flexibility (liquefied) •Loads/actions included: •Dead Load •Differential settlement •Based on the analysis groundwater elevation •40% in 60 feet •Estimate demands on structural members •Focus on PFMs and deficiencies from Tier 1 PS15-06 TM4 Appendix C 595 Orange County Sanitation District City Water PS –Ground Deformation Patterns 87 •Longitudinal Application Pattern 1 (stiff @ left end) PS15-06 TM4 Appendix C 596 Orange County Sanitation District City Water PS –Ground Deformation Patterns 88 •Longitudinal Application Pattern 2 (stiff in middle) PS15-06 TM4 Appendix C 597 Orange County Sanitation District City Water PS –Ground Deformation Analysis 89 •In-plane Shear –Pattern 2 PS15-06 TM4 Appendix C 598 Orange County Sanitation District City Water PS –Ground Deformation Analysis 90 •Out-of-plane Shear –Pattern 2 PS15-06 TM4 Appendix C 599 Orange County Sanitation District City Water PS –Ground Deformation Analysis 91 •Out-of-plane Bending –Pattern 2 PS15-06 TM4 Appendix C 600 Orange County Sanitation District City Water PS –Ground Deformation Analysis 92 •Tension in Wall –Pattern 2 PS15-06 TM4 Appendix C 601 Orange County Sanitation District City Water PS –GDR Preliminary Findings 93 Item Demand Capacity m-factor GDR DCR In-plane shear @ south pier 20 psi 99 psi 2.0 0.10 In-plane shear @ south wall 40 psi 99 psi 2.0 0.20 In-plane shear @ west wall 64 psi 99 psi 2.0 0.32 Out-of-plane shear 7 psi 95 psi N/A 0.07 Out-of-plane bending, Mx/My 2.4 k-ft / 0.40 k-ft 1.4 k-ft / 5.1 k-ft N/A 1.71 / 0.08 Tension in wall 83 psi 128 psi 2.0 0.32 PS15-06 TM4 Appendix C 602 Orange County Sanitation District City Water PS –Preliminary Findings 94 Item GMR DCR GMR DCR Combined DCR In-plane shear @ south pier 1.45 0.10 1.45 In-plane shear @ south wall 0.66 0.20 0.69 In-plane shear @ west wall 0.35 0.32 0.47 Out-of-plane shear 0.26 0.07 0.27 Out-of-plane bending, Mx/My 1.79 / 0.20 1.71 / 0.08 2.48 / 0.22 Tension in wall 0.65 0.32 0.72 PS15-06 TM4 Appendix C 603 Orange County Sanitation District City Water PS –Preliminary Mitigation List 95 •Tie slab to wall/stem wall •Upgrade beam connections to roof diaphragm (4 locations) •Reinforce overstressed wall pier @ south wall •Supplement wall with horizontal girts PS15-06 TM4 Appendix C 604 Orange County Sanitation District City Water PS –Additional Actions 96 •Use results to judge performance of similar structures •Review ground deformation estimates for similar structures •Using same FEM model, run analyses as required for: •Increased and/or decreased magnitudes of settlement •Perform independent lateral stability check for unique conditions •BSE-2E analysis PS15-06 TM4 Appendix C 605 Orange County Sanitation District Plant 2-Secondary Clarifiers A-L Update 97 PS15-06 TM4 Appendix C 606 Orange County Sanitation District •736 feet long •250 feet wide •Wall thickness varies •Multiple expansion gaps within the clarifiers •Expansion gap separation with the Aeration Basins (less than 4%) •Secondary Clarifiers could not be classified as any building type Plant 2-Secondary Clarifiers A-L Update PS15-06 TM4 Appendix C 607 Orange County Sanitation District Plant 2-Secondary Clarifiers A-L Update PS15-06 TM4 Appendix C 608 Orange County Sanitation District SC A-L -Structural Summary 100 PS15-06 TM4 Appendix C 609 Orange County Sanitation District Potential Failure Modes Description PFM1 Ground shaking (GS) -Bending failure of walls (various load cases w/ adjacent clarifiers out of operation) PFM2 GS -Shear failure of walls (various load cases w/ adjacent clarifiers out of operation) PFM3 GS -Failure of beams and columns supporting sludge collector PFM4 GS -Failure of supports for walkways and precast concrete troughs PFM5 GS -Ground deformation due to liquefaction/lateral spread 5A -Horizontal spread across expansion joints allows catastrophic leakage 5B -Differential settlement across expansion joints allows catastrophic leakage or impairs flow. PFM6 Liquefaction -Loss of anchor capacity 6A -Buoyant uplift on structure 6B -Localized failure of mat PFM7 Liquefied soils adjacent to wall -failure in walls due to increased soil pressures (hydrostatic + dynamic) Digester 16 –Potential Failure Modes 101 PS15-06 TM4 Appendix C 610 Orange County Sanitation District Potential Failure Modes Description PFM8 Lateral spread 8A -Horziontal/vertical offset of expansion joint 8B -Lateral spread in transverse direction (towards Marsh) can damage the beams, which span across east-west running expansion joints. 8C -Lateral spread in transverse direction can collapse the north clarifier slab over the tunnel (it is sitting on an expansion joint shelf on the Aeration Basins). PFM9 Liquefaction -Differential settlement 9A -north slab of secondary clarifier drops down relative to support at Aeration Basin south wall causing bending/shear failure. 9B -north slab of secondary clarifier drops at the Aeration Basin side causing bending/shear failure. Digester 16 –Potential Failure Modes 102 PS15-06 TM4 Appendix C 611 Orange County Sanitation District Secondary Clarifiers FE Model PS15-06 TM4 Appendix C 612 Orange County Sanitation District Secondary Clarifiers –Ground Shaking 104 PS15-06 TM4 Appendix C 613 Orange County Sanitation District Secondary Clarifiers –Ground Deformation 105 PS15-06 TM4 Appendix C 614 Orange County Sanitation District Secondary Clarifiers –Ground Deformation 106 PS15-06 TM4 Appendix C 615 Orange County Sanitation District •Option 1: Ground improvement to limit lateral spread •Construct ground improvement shear panels in front of (including pathway) and below portion of secondary clarifiers. •Design spacing and strength to limit failure surface behind the improved zone •Target displacement reduction to limit potential separation of clarifier joints •Ground improvement methods: Auger soil mixing, cutter soil mixing, slurry wall method, jet grouting, … •Key ground improvement elements: •Large footprint •Must achieve high strength and/or large “replacement volume” •“Key” improvement below lateral spread zone (~ Elev. -25 feet) •Localized settlement reduction may exacerbate differential settlement to structure SC A-L –Mitigation Concepts –PFM8 107 PS15-06 TM4 Appendix C 616 Orange County Sanitation District •Option 1: Ground improvement to limit lateral spread SC A-L –Mitigation Concepts –PFM8 108 Ground Improvement Zone PS15-06 TM4 Appendix C 617 Orange County Sanitation District •Option 2: Subsurface retaining wall to limit lateral spread •Construct wall within available room between structures and marsh •Design wall to resist earth pressure from lateral spread without excessive deflection •Wall types: secant pile wall, cutter soil mix wall, … •Key wall elements •Significant depth (~100 ft), founded below liquefaction zone •Heavily reinforced to limit deflections •No mitigation for settlement below structure SC A-L –Mitigation Concepts –PFM8 109 PS15-06 TM4 Appendix C 618 Orange County Sanitation District •Ground improvement below structure to reduce impacts of differential settlement •Ground improvement would be required below full structure footprint •Given large dimensions of structure and depth of liquefiable zone, may not be viable to construct without working within structure footprint •Ground improvement methods: chemical grouting, jet grouting, … •Key ground improvement elements: •Large footprint •Must achieve significant grout penetration and distribution •Depth of improvement (e.g. 40 ft below clarifier) will depend on acceptable settlements –may not need complete improvement if differential settlement is reduced sufficiently. •Improvement for settlement will also limit lateral spread SC A-L –Mitigation Concepts –PFM9 110 PS15-06 TM4 Appendix C 619 Orange County Sanitation District Discussion 111 PS15-06 TM4 Appendix C 620 \Mtg Minutes - OCSD TM3 Review Mtg 11-5-18 MEETING MINUTES SUBJECT: PS15-06 Technical Memorandum #3 Review Meeting DATE: Monday, November 5, 2018 TIME: 10:00 a.m. PST LOCATION: OCSD Administration Building, Conference Room A MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt Carollo – James Doering, Doug Lanning, Steve Hough InfraTerra – Ahmed Nisar, Nick Doumbalski (via phone) OCSD – Don Cutler, Mike Lahlou, Eros Yong, Dean Fisher, Jeff Mohr, Mike Dorman, Martin Dix, Nasrin Nasrollahi Jacobs (via phone) – Kirk Warnock, Jeong Yang 1. Introduction/Safety Moment C. Conkle presented safety moment. Topic: Drowsy Driving. 2. Review Project Objectives C. Conkle described the objectives of the meeting as outlined on the attached slides. 3. Role of TM3 in Overall Scope o Performance standards based on ASCE 41-13 o Liquefaction induced settlements • Plant 1: 2” to 10” at ground surface - free field settlement calculation • Plant 2: 2” to >10” at ground surface - free field settlement calculation • Structures that are not color-coded in the figure are not included in the study o Liquefaction induced lateral spreading PS15-06 TM4 Appendix C 621 PS15-06 Technical Memorandum #3 Review November 5, 2018 Page 2 • Plant 1: up to about 3 feet near river frontage to a cutoff within the plant where lateral spreading is not expected to show up • Plant 2: up to about 6 feet near river frontage and up to about 5 feet at Talbert Marsh • Reduction in lateral spread magnitude with distance from free face 4. Overview of Identified Vulnerabilities o Developed a series of Potential Failure Modes (PFMs) evaluated relative to performance criteria for each structure o Overview of Plant vulnerability figures - Color coding corresponds to having at least 1 failure mode that didn’t meet a performance criterion o Question (S. Hough): Steve asked whether the selection of structures was made based on age and anticipated improved seismic performance. He noted some of the key sources of vulnerability (e.g. lateral spread) may not have been considered for some of the structures that are outside of scope. • Answer: The team described the process for selection of the structures in the study and agreed that other more recently built structures may also be exposed to the lateral spreading hazard. o Question (M. Dix): Is Hospital design similar to the requirements of Class I. • Answer (Nisar): Hospitals are designed to a different standard. 5. Standard Mitigations o Mitigation tables address PFMs that have a vulnerability o Developed a toolbox of standard mitigations for structural and geotechnical vulnerabilities 6. Geotechnical Mitigation Needs o Figures show geotechnical mitigation needs, and opportunities for lateral spread mitigation o Question (E. Yong): If you are doing new construction, are the options for mitigation different? • Answer (Conkle): Yes, with access to the building footprint, there are more options on the table from an economic perspective. o Geotechnical mitigation below secondary clarifiers for settlement would meet the needs for lateral spread as well. If not performed, extending LS mitigation wall may be recommended. o Localized lateral spread mitigation could have an impact in increasing differential lateral spread effects PS15-06 TM4 Appendix C 622 PS15-06 Technical Memorandum #3 Review November 5, 2018 Page 3 o Question (J. Mohr): Will this project include a recommendation for lateral spread mitigation along the plant, or is it out of scope? • Answer: Currently we plan to make a recommendation based solely on the findings for specific structures in this study. Ultimately there may be a benefit to viewing this mitigation form a plant wide perspective and incorporating effects on other structures. o Question (E. Yong): Will lateral spread mitigation address both hazard levels? • Answer: Yes, the demands (settlements/lateral spread) are similar at both hazard levels. The performance levels are different for the structures however. 7. Characteristic Vulnerabilities/Structures o Roof Diaphragm Strengthening (B1) - a few structures between both plants o Concrete infill strengthening - 1 at Plant 1; 4 at Plant 2 o P1 Control center has issues with drift and torsional response - Mitigation is adding bracing to make it a braced frame building o P1 Central Power Generation Building - lack of shear wall bracing; discontinuous shear wall – Mitigation is to provide concrete infill and shear wall addition to basement o P2 Maintenance Building - high drift and high flexural stress in columns and beams; concrete cladding prevents moment frames from doing their job - Mitigation is adding bracing o P2 PEPS & MAC Exemplar - Ground Deformation - Differential settlement results in tension; rigid structures often don’t respond well to differential settlement o Other liquefaction hazards • Lateral spread • Uplift / Active Earth Pressure Discussed OOBS example where different uplift on differently loaded parts may result in damage o Digesters • Lateral spread is the largest vulnerability - resulting in damage to piles • Piles can take some amount of movement, but after 12” or so, they start to have damage o Secondary Clarifiers • Large footprint of structures and expansion joints are concern • Clarifiers at Plant 2 - expansion joints in walls, but not in floor slab. Less susceptible to lateral spread, but differential settlement results in opening and rotation of wall joints • Plant 1 clarifiers are on piles, but have expansion joints that cut through the slab, so susceptible to lateral spread which pulls apart the sections at the joints o Surge Towers PS15-06 TM4 Appendix C 623 PS15-06 Technical Memorandum #3 Review November 5, 2018 Page 4 • Very large lateral spread deformations, which could impact the dresser couplings • Surge towers may be subjected to some tilt, and could still function, but not likely to collapse, if the connection is not disengaged o Gas Holders • Relatively light structures • Largest vulnerability is differential settlement - similar anchor systems at other sites have experienced damage during past earthquakes 8. Next Steps (Discussions of TM4/Relationship with TM3) o TM4 Process • Risk-based prioritization of seismic projects relative to each other • Recommended mitigation measures for seismic vulnerabilities • Planning-level cost estimates for mitigation measures • Evaluation of mitigation vs. replacement • Additional considerations Effectiveness, constructability, cost, post-event repair cost, duration, and consequences vs. mitigation • Recommended process for incorporating seismic projects into FMP o Topics for Discussion • Lateral Spreading • Likelihood of Seismic Failure (scoring) • Consequence of Seismic Failure and Importance Factors (IF) • Risk = Likelihood x Consequence • The following criteria will be considered considered in the development of recommended projects Effectiveness of seismic mitigation Constructability of seismic mitigation Construction cost of seismic mitigation Post-event repair cost, duration, and CoSE vs. mitigation 9. Q&A o Question (J. Mohr): How do you rank life safety relative to water in/water out? Does life safety trump all and move something to the top of the list automatically? Many of the structures which have life safety implications are not currently on the radar for FMP purposes. • Discussion: The group discussed how this will be handled in the consequence evaluation. Additional discussion is needed. o Question (E. Yong): How do you handle probability of failure of multiple elements of a single process at the same time? PS15-06 TM4 Appendix C 624 PS15-06 Technical Memorandum #3 Review November 5, 2018 Page 5 • Answer (Lanning): This will be addressed in the development of recommended projects. May be able to live with damage to duplicate process elements. o Comment (J. Mohr): It’s important to not take this study too far into the design realm. Complete it soon at a planning level to aid in decision making. o Comments (J. Mohr and others ): OCSD noted that condition and remaining useful life are important considerations in the decision making process. These factors will be accounted for in the decision making process. ***** Attachments • PowerPoint slides from Presentation 11-5-18 PS15-06 TM4 Appendix C 625 Orange County Sanitation District Orange County Sanitation District TM3 MEETING SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 NOVEMBER 5, 2018 PRESENTED BY: Geosyntec Team PS15-06 TM4 Appendix C 626 Orange County Sanitation District Agenda •Introductions/Safety Moment •Role of TM3 in Overall Scope •Overview of Identified Vulnerabilities (Plant 1 and 2) •Standard Mitigations (Structural/Geotechnical) •Geotechnical Mitigation Needs (Plant 1 and 2) •Characteristic Vulnerabilities/Structures •Next Steps •Questions/Discussion 2 PS15-06 TM4 Appendix C 627 Orange County Sanitation District Safety Moment –Drowsy Driving The Warning Signs of Drowsy Driving –Yawning or blinking frequently. –Difficulty remembering the past few miles driven. –Missing your exit. –Drifting from your lane. –Hitting a rumble strip 3 –If you experience any of the warning signs of drowsy driving pull over to a safe place and take a 15-20 minute nap or change drivers. –Simply turning up the radio or opening the window are not effective ways to keep you alert! PS15-06 TM4 Appendix C 628 Orange County Sanitation District Safety Moment –Drowsy Driving Drowsy Driving Is Similar to Drunk Driving •Being awake for at least 18 hours is the same as someone having a blood content (BAC) of 0.05%. •Being awake for at least 24 hours is equal to having a blood alcohol content of 0.10%. This is higher than the legal limit (0.08% BAC) in all states. Prevention •Get enough sleep! Most adults need at least 7 hours of sleep a day •Develop good sleeping habits such as sticking to a sleep schedule. •If you have a sleep disorder or have symptoms of a sleep disorder such as snoring or feeling sleepy during the day, talk to your physician about treatment options. •Avoid drinking alcohol or taking medications that make you sleepy. Be sure to check the label on any medications or talk to your pharmacist. 4 PS15-06 TM4 Appendix C 629 Orange County Sanitation District Meeting Objectives 5 •Provide Overview of Identified Vulnerabilities •Provide Overview of Recommended Mitigations •Discuss the relationship between TM3 and upcoming TM4 •Prepare team for review of TM3 draft document PS15-06 TM4 Appendix C 630 Orange County Sanitation District Role of TM3 in Overall Scope 6 •Presentation of Results of Task 2 and Task 3 •Identification of Structural Vulnerabilities •Identification of Recommended Mitigations (Geotechnical and Structural) •Set the stage for costing and development of alternatives (including operational and replacement) PS15-06 TM4 Appendix C 631 Orange County Sanitation District Performance Standards (ASCE 41-Based) 7 Structure Type Class Seismic Hazard Level Structural Performance Level Non-Structural Performance Level Building I BSE-1E (20% in 50 yrs) Immediate Occupancy (S-1) Position Retention (N-B) BSE-2E (5% in 50 yrs) Life Safety (S-3) Not Considered (N-D) Building II BSE-1E (20% in 50 yrs) Life Safety (S-3) Life Safety (N-C) BSE-2E (5% in 50 yrs) Collapse Prevention (S-5) Not Considered (N-D) Non- Building (Liquid- Containing Structures) I BSE-1E (20% in 50 yrs) Immediate Occupancy (S-1) Position Retention (N-B) BSE-2E (5% in 50 yrs) Life Safety (S-3) Not Considered (N-D)PS15-06 TM4 Appendix C 632 Orange County Sanitation District Liquefaction Induced Settlement (Plant 1) 8 PS15-06 TM4 Appendix C 633 Orange County Sanitation District Liquefaction Induced Lateral Spreading (Plant 1) 9 PS15-06 TM4 Appendix C 634 Orange County Sanitation District Lateral Spreading (Plant 1) 10 PS15-06 TM4 Appendix C 635 Orange County Sanitation District Liquefaction Induced Settlement (Plant 2) 11 PS15-06 TM4 Appendix C 636 Orange County Sanitation District Liquefaction Induced Lateral Spreading (Plant 2) 12 PS15-06 TM4 Appendix C 637 Orange County Sanitation District Liquefaction Settlement (Plant 2) 13 PS15-06 TM4 Appendix C 638 Orange County Sanitation District PFM Example -Table 1-10. CenGen 14 Notes: (1) T1, T2, T3 –ASCE 41-13 Tier 1, Tier 2, Tier 3 (2) DCR –Demand-to-Capacity Ratio (reported to one decimal place) (3) Performance Objectives as per TM1 (4) See Section 6.0 for mitigation options (5) Tier 1 evaluations do not include m-factors per ASCE 41-13* Also does not meet life safety for BSE 1E PF M Description An a l y s i s Ap p r o a c h 1 BSE 1E (20% in 50) BSE 2E (5% in 50) Me e t s Pe r f o r m a n c e Ob j e c t i v e s ? 3 Comments4 DC R 2 AS C E 4 1 -13 m-fa c t o r DC R 2 AS C E 4 1 -13 m-fa c t o r 3 Insufficient lateral bracing along the west side of the building T2 3.2 2.0 (IO- Reinforced Concrete In- Plane Shear Wall) > 2.0 2.0 (LS- Reinforced Concrete In- Plane Shear Wall) IO (BSE 1E): N* LS (BSE 2E): N The shear walls along the west side of the building are minimal and lack adequate capacity to resist the seismic loads of the building. The balance of the walls are compliant. 4 Wall anchorage at the high roof north and south walls T1 > 20 (5) > 1.0 (5) IO (BSE 1E): N* LS (BSE 2E): N The north and south walls use pilasters to brace the walls for out-of-plane loads, but these same pilasters are not anchored to the roof framing. The DCR reported is an estimate of what little capacity the deck provides to resisting these loads. This is a significant deficiency at all performance levels. 5 High roof diaphragm shear T2 0.8 1.0 (force- controlled) 1.2 1.0 (force- controlled) IO (BSE 1E): Y LS (BSE 2E): N Anchor bolt shear is limiting strength and is force-controlled. 6 Low roof diaphragm shear T2 0.9 1.0 (force- controlled) 1.3 1.0 (force- controlled) IO (BSE 1E): Y LS (BSE 2E): N Anchor bolt shear is limiting strength and is force-controlled. 8 Bending/shear failure of piles due to lateral spread (surface PGD = 8-inches) T1/2 1.3 2.0 (IO for columns) 1.3 3.0 (LS for columns) IO (BSE 1E): Y LS (BSE 2E): Y 4.5” (estimate at the pile head) lateral spread toward Santa Ana River at the foundation level. Exemplar is Digester 16. DCR is the near pile top displacement over pile top displacement at yield (3.5”). PS15-06 TM4 Appendix C 639 Orange County Sanitation District Overview of Identified Vulnerabilities (Plant 1) 15 PS15-06 TM4 Appendix C 640 Orange County Sanitation District Overview of Identified Vulnerabilities (Plant 2) 16 PS15-06 TM4 Appendix C 641 Orange County Sanitation District Example Mitigation Table 1-10.CenGen 17 PF M Description Mitigation Notes on Application of Mitigation 3 Insufficient lateral bracing along the west side of the building Standard Structural Mitigation E Applies over 24 lineal feet x 9-ft tall windows. 4 Wall anchorage at the high roof north and south walls Standard Structural Mitigation A2 (High) (SIM) Similar with new steel roof framing members. Provide at (6) locations. 5 High roof diaphragm shear Standard Structural Mitigation B2 Supplement existing anchors at 20” OC (total of 90 epoxy anchors). 6 Low roof diaphragm shear Standard Structural Mitigation B2 Supplement existing anchors at 20” OC (total of 60 epoxy anchors). PS15-06 TM4 Appendix C 642 Orange County Sanitation District Standard Structural Mitigations 18 ID Mitigation Name Description A1 Wall anchorage, Type 1 Provision of steel angles or WT struts with steel hardware and epoxied anchors into the existing wall or perimeter roof beam at 8 feet on center. Struts to extend into the diaphragm as required to develop the wall anchorage force. Struts are to be field welded to the roof deck. A2 Wall anchorage, Type 2 Provision of new steel welded or bolted connections to existing beams that are epoxied into the existing wall, pilaster, or perimeter concrete beam. Mitigation includes additional roof deck welding as required for full wall anchorage force development into the diaphragm. Magnitude of work is expressed as High, Medium, and Low. B1 Roof diaphragm strengthening, Type 1 Replace existing roof deck to the extent the deck is deficient and provide supplemental steel roof framing as required. B2 Roof diaphragm strengthening, Type 2 Provide additional epoxy anchors at the existing ledger angle. Drill anchors through the existing ledger angle. C1 Foundation Tie, Type 1 Provision of steel angle tie plate that is anchored into the wall and slab at the interior of the building using epoxy anchors. Angles are assumed to be required at a spacing of 4 feet on center. C2 Foundation Tie, Type 2 Provide an exterior cast-in-place concrete tie beam that is cast at the exterior of the building below grade and epoxy doweled into the existing wall and footings (continuous or isolated pad footings). D OOP Wall Bracing Provision of vertical steel tube or steel channel members to reduce the horizontal span of the wall, especially where pilasters occur. The vertical member is to be anchored to the masonry or concrete wall with epoxy anchors regularly spaced. The vertical member is required to be braced to the foundation and to the roof framing with additional hardware and framing members as required. E Cast-in-place Concrete Infill Infill existing window with cast-in-place concrete. Install reinforcing steel epoxy dowels into existing wall, beam, and columns at the perimeter of the existing window.PS15-06 TM4 Appendix C 643 Orange County Sanitation District Standard Geotechnical Mitigations 19 ID Mitigation Name Description A1 Ground Improvement Buttress Construct a cemented mass of in-situ soil (by deep soil mixing, jet grouting, or similar method) between the structure and the Santa Ana River and/or Talbert Marsh, as applicable. A2 Secant Pile Wall Construct a secant pile wall comprised of overlapping soil-mixed columns with embedded steel reinforcement to resist liquefaction-induced lateral spreading towards the Santa Ana River and/or Talbert Marsh. B1 Ground Improvement Under Slab Foundation Use one of several available ground improvement techniques to reduce the liquefaction potential of specified soil strata beneath the footprint of the entire structure. B2 Ground Improvement Under Perimeter Footings Use one of several available ground improvement techniques to reduce the liquefaction potential of a specified strata of soil directly beneath the structure footings. C Ground Improvement Around Perimeter of Submerged Walls Treat the soils immediately outside basement walls, using one of several available ground improvement techniques, to limit liquefaction in soil backfill and reduce the potential for increased lateral earth pressure on submerged walls. PS15-06 TM4 Appendix C 644 Orange County Sanitation District Standard Geotechnical Mitigations 20 PS15-06 TM4 Appendix C 645 Orange County Sanitation District Standard Geotechnical Mitigations 21 PS15-06 TM4 Appendix C 646 Orange County Sanitation District Standard Geotechnical Mitigations 22 PS15-06 TM4 Appendix C 647 Orange County Sanitation District Standard Geotechnical Mitigations 23 PS15-06 TM4 Appendix C 648 Orange County Sanitation District Geotech Mitigation Needs (Plant 1) 24 PS15-06 TM4 Appendix C 649 Orange County Sanitation District Geotech Mitigation Needs (Plant 2) 25 PS15-06 TM4 Appendix C 650 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 26 Roof Diaphragm Strengthening B1 Replace roof decking Supplement w/ steel truss bracing PS15-06 TM4 Appendix C 651 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 27 Roof Diaphragm Strengthening –Plant 1 PS15-06 TM4 Appendix C 652 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 28 Roof Diaphragm Strengthening –Plant 2 PS15-06 TM4 Appendix C 653 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 29 Concrete In-fill (E) Moment Concrete Frame P2 12kV Service Center P1 Central Power Generation Wall and low beam restrains frames No lateral bracing for the high roof PS15-06 TM4 Appendix C 654 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 30 Concrete In-fill Concrete Infill (E) Moment Frame Concrete Infill (typ) P2 12kV Service Center P1 Central Power Generation PS15-06 TM4 Appendix C 655 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 31 Concrete In-fill PS15-06 TM4 Appendix C 656 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 32 Concrete In-fill PS15-06 TM4 Appendix C 657 Orange County Sanitation District Characteristic Vulnerabilities/ Structures P1 Control Center 33 •High drift •High torsional response •Column anchorage cannot develop column capacity •Pre-Northridge moment frame connections (non-ductile) •Low panel zone shear strength •Frame beams lack adequate bottom flange bracing PS15-06 TM4 Appendix C 658 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 34 P1 Control Center Braced Frames (typ of 8) PS15-06 TM4 Appendix C 659 Orange County Sanitation District Characteristic Vulnerabilities/ Structures P1 Central Power Generation Building 35 Lack of Shear Wall Bracing along the West Wall Discontinuous Shear Wall PS15-06 TM4 Appendix C 660 Orange County Sanitation District Characteristic Vulnerabilities/ Structures P1 Central Power Generation Building 36 Concrete Infill (typ) Concrete Shear Wall Addition to Basement PS15-06 TM4 Appendix C 661 Orange County Sanitation District Characteristic Vulnerabilities/ Structures P2 Maintenance Building 37 •High drift •High flexural stress in columns and beams •Cladding restrains frames •Pre-Northridge moment frame connections (non-ductile) •Low panel zone shear strength •Weak columns relative to beams •Columns are non-compact PS15-06 TM4 Appendix C 662 Orange County Sanitation District Characteristic Vulnerabilities/ Structures P2 Maintenance Building 38 Steel Braced Frame Additions (typ) PS15-06 TM4 Appendix C 663 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 39 P2 PEPS & MAC –Ground Deformation Ground deformation pattern Wall tension PS15-06 TM4 Appendix C 664 Orange County Sanitation District Characteristic Vulnerabilities/ Structures 40 Other Liquefaction Hazards •Lateral Spread •Pile shear / bending failure •Foundations and walls not tied together •Expansion joints pull apart or shear •Differential spread with collision •Varying foundation depths •Passive pressure application •Uplift / Active Earth Pressure •Failure of soil anchors •Uplift pressures on base slabs •Increased active lateral earth pressures on basement walls P2 Power Building C OOBS PS15-06 TM4 Appendix C 665 Orange County Sanitation District Characteristic Vulnerabilities Digesters 41 11 12 13 14 15 16 6 7 8 9 10 5 35” 17” 16”11” PS15-06 TM4 Appendix C 666 Orange County Sanitation District Characteristic Vulnerabilities/ Structures Clarifiers –Plant 2 42 2010 Chile Earthquake Expansion Joint Expansion Joint Expansion Joint not likely under the wall Scott Tunnel Expansion Joint Construction Joint Construction Joint PS15-06 TM4 Appendix C 667 Orange County Sanitation District Characteristic Vulnerabilities/ Structures Clarifiers –Plant 1 43 Expansion Joint Existing Conditions 6”4”3” 2” After Geotechnical Mitigation 0.7” 1”1.3”2” PS15-06 TM4 Appendix C 668 Orange County Sanitation District Characteristic Vulnerabilities/ Structures Surge Towers 44 65” Dresser coupling will disengage due to differential movement PS15-06 TM4 Appendix C 669 Orange County Sanitation District Characteristic Vulnerabilities/ Structures Gas Holders 45 PS15-06 TM4 Appendix C 670 Orange County Sanitation District •Risk-based prioritization of seismic projects relative to each other •Recommended mitigation measures for seismic vulnerabilities •Planning level cost estimates for mitigation measures •Evaluation of mitigation vs. replacement •Additional considerations •Effectiveness of seismic mitigation •Constructability of seismic mitigation •Construction cost for seismic mitigation •Post-event repair cost, duration, and CoSE vs. mitigation •Recommended process for incorporating seismic projects into FMP Looking Ahead to TM 4 46 PS15-06 TM4 Appendix C 671 Orange County Sanitation District Lateral spreading •Evaluate mitigation, cost, and priority on a structure-by- structure basis? •Evaluate on a broader basis? TM4 Discussion Topics 47 PS15-06 TM4 Appendix C 672 Orange County Sanitation District Confirm: •LoSF is likelihood that structure cannot meet performance objectives for BSE-1E and BSE-2E seismic hazard levels •Identify controlling failure mode TM4 Discussion Topics 48 PS15-06 TM4 Appendix C 673 Orange County Sanitation District Confirm CoSF and Importance Factors: •Life safety, IF = 100% •Water in/out impacts, IF = 75% •Regulatory, IF = 50% •Stakeholder Commitments, IF = 37.5% •Financial, IF = 25% •Public Impacts, IF = 16.5% Note: Blue consequences are from FMP with IF reduced by 50% TM4 Discussion Topics 49 PS15-06 TM4 Appendix C 674 Orange County Sanitation District Confirm the following will not be used in prioritization scoring, but may be used in final project scheduling on a case-by-case basis using the team’s best judgment: •Effectiveness of seismic mitigation •In general, “mitigation” provides compliance with performance objectives for BSE-1E and BSE-2E seismic hazard levels --but this may not always be feasible/practical •Constructability of seismic mitigation •Construction cost for seismic mitigation •Post-event repair cost, duration, and CoSE vs. mitigation TM4 Discussion Topics 50 PS15-06 TM4 Appendix C 675 Orange County Sanitation District TM4 Discussion Topics Confirm CoSE initiative to integrate seismic projects with FMP 51 PS15-06 TM4 Appendix C 676 Orange County Sanitation District •Review of Draft TM3 •Proceed with TM4 •Finalization of Mitigation Alternatives •Project prioritization Next Steps 52 PS15-06 TM4 Appendix C 677 Orange County Sanitation District Discussion 53 PS15-06 TM4 Appendix C 678 Orange County Sanitation District Thank You! 54 PS15-06 TM4 Appendix C 679 HL1635-04\Mtg Minutes - OCSD TM4 Project List Mtg 1-9-19 MEETING MINUTES SUBJECT: PS15-06 TM4 Project List Review Meeting DATE: Wednesday, January 9, 2019 TIME: 8:00 a.m. PST LOCATION: OCSD Eng. & Const. Conference Room 1 MEETING ATTENDEES: Geosyntec – Chris Conkle, Chris Hunt (via phone) Carollo – James Doering, Steve Hough, Doug Lanning InfraTerra – Ahmed Nisar OCSD – Don Cutler, Mike Lahlou, Eros Yong, Dean Fisher, Jeff Mohr, Mike Dorman, Martin Dix, Kathy Miller, Brian Terrell, Adnan Rahman, Andrew Brown Jacobs (via phone) – Kirk Warnock 1. Introduction/Safety Moment Chris presented a safety moment on earthquake alerts. Parties introduced themselves. Chris presented the objectives of the meeting. 2. TM4 Overview Chris provided an overview of how TM4 fits into the project and the current activities. 3. Cost Estimating Process Doug: Cost estimation basis, project level allowance 30%, same as FMP. No comments on cost estimation process. 4. Review of: Risk Rankings: o Doug: Noted that there were no governing Stakeholder or Public Impact rankings. o James: Clarified what confidence ratings (L/M/H) represent.Confidence L, M, H, but conservative. Low means with more assessment risk could be lower; however, unlikely that it would be higher. PS15-06 TM4 Appendix C 680 PS15-06 TM4 Project List Review Meeting January 9, 2019 Page 2 HL1635-04\Mtg Minutes - OCSD TM4 Project List Mtg 1-9-19 o Don: provided a brief description of lateral spread phenomenon. Mitigation Costs: Facility value means replacement value in kind. This cost will not include demolition, ground improvement, or interim measures needed to sequence work or provide for temporary function. Project Recommendations: o Jeff More: Some clarity on the structural cost is needed. Lateral spread for the entire plant. This project is District wide to flag facilities and not to get bogged down on a structure/structure basis. o Jeff More: We need to understand confidence in geotechnical costs. What is the confidence that the costs will not quadruple? After all, we are going under big structures, cutting through slabs etc. 5. Q&A Kathy: I thought Plant 2 was more risky because of fault rupture issue, but the risk scores for both plants are similar. – AN, CH, CC – risk is driven by liquefaction, which can occur in many events and fault rupture is only but one event. The shaking at both plants is similar. Discussion of ground deformation probabilities. Jeff More also commented on fault rupture risk and agreed/understood the reasoning provided by the team. Kathy: Why is the risk zero for truck loading area? Mike: Would the risk ranking change if we do not build the wall? Chris and Doug: risk ranking is irrespective of mitigation. Aros: Lateral spread mitigation for entire P2, we may choose not to do the entire plant. For example, we may only protect critical assets, such as headworks, etc. Chris: We are updating project development criteria, which may lead to spreading the cost of the wall over new structures. Jeff: One recommendation from the study will be to build the wall and then another study to study the wall in detail. There was a question on what other utilities are doing, or is it that OCSD is doing unprecedented work? Jeff: wastewater plants are close to waterfront, do others have lateral spread problems? AN – SFPUC is spending billions of dollars on their wastewater system, but that includes collection system and piping, etc. For our Portland study, there is a very significant lateral spread risk along the Willamette and Columbia Rivers, but PS15-06 TM4 Appendix C 681 PS15-06 TM4 Project List Review Meeting January 9, 2019 Page 3 HL1635-04\Mtg Minutes - OCSD TM4 Project List Mtg 1-9-19 they have pipelines in this zone, and there are projects to directionally drill pipelines under the spread zone. Jeff: we have major pipelines along the river. Jeff: Any consideration given to the reduction in lateral spread because of shielding of structures. AN there may be some effect, but Christchurch, etc. showed widespread issues because lateral spread is an area-wide issue. Jacobs: Was the cost of structural mitigation based on a per square foot basis? James and Doug: No, we did planning level material takeoffs. Question – why are there a lot of cases that have lateral spread, but controlling failure is GS? Don: OOBS vulnerable from LS because? Chris: Cannot do LS mitigation at OOBS because it extends into the river. James: unbalanced uplift at OOBS. OOBS should be changed to grey. There was some confusion why some structures in LS zone not shown with LS check mark. Kathy: where do we go from here? Doug: prioritized list is there. If there is some adjustment that needs to be done, we should do it. Comment: We can group projects in different ways. Comment: present wall in different way, do nothing, accept risk. Jeff: Is implementation plan part of this work? Aros: No. Implementation plan is for management to do. Kathy: OCSD needs to come up with an implementation plan. Jeff: Study will be completed this year. Plan will be developed later this year. Occupied buildings take steps sooner: Maintenance building and control center Tier 1. Control building, maintenance building certainly need to do something about. Ops building, we don’t take on because we have another plan for that. Model ops center, if not a big effort. 12kv, if simple. Jeff: Focus on wrapping up the study. Important thing with big master plan-type studies is to wrap it up and not go on and on. OCSD to do implementation plan. ***** PS15-06 TM4 Appendix C 682 PS15-06 TM4 Project List Review Meeting January 9, 2019 Page 4 HL1635-04\Mtg Minutes - OCSD TM4 Project List Mtg 1-9-19 Attachments: Plant 1 Structures Risk Ranking 1-9-19. pdf Plant 2 Structures Risk Ranking 1-9-19.pdf PowerPoint Slides from Presentation: TM4 Project Recommendations – Seismic Evaluation of Structures at Plants 1 & 2 PS15-06 TM4 Appendix C 683 Plant 1 ‐ Risk Ranking Structure Number Structure Name GS DS LS Li f e S a f e t y Pr i m a r y Tr e a t m e n t Re g u l a t o r y St a k e h o l d e r Fi n a n c i a l Pu b l i c I m p a c t Overall RoSF Co n f i d e n c e Structural Mitigation Cost Geotechnical Mitigation Cost2 Total Mitigation Cost Facility Value No Project, LoSF = 0 Address with Previously Planned Project Mitigate with New Project Identified in TM3 Replace Facility 8 Control Center x x 25 L/M $7,260,000 $0 $7,260,000 $16,200,000 X ? 9 12 kV Service Center x x 25 H $230,000 $0 $230,000 $42,100,000 X 31 Buildings 5 and 6 x x 25 L/H $1,070,000 $0 $1,070,000 $4,893,000 X 2 Blower Building (AS1) and PEPS x x x 20 H $2,140,000 $0 $2,140,000 $109,668,000 X‐048 10 Central Power Generation Building x x 20 H $1,530,000 $1,740,000 $3,270,000 $154,800,000 P1‐1271 12 Secondary Clarifiers 1‐26 x x x 20 H $0 $0 $0 $219,336,000 X1 30 Shop Building B and Building 3 x x 20 M $440,000 $0 $440,000 $4,230,000 X 32 Auto Shop x x 20 M/H $410,000 $0 $410,000 $1,853,000 X 21 Digesters 11‐16 x x 16 H $0 $0 $0 $66,000,000 X1 1 Waste Sludge Thickeners (DAFT) Pump Room x x x 15 M/H $840,000 $0 $840,000 $4,000,000 X‐0431 26 Solids Storage Facility x x 15 L/M $20,000 $0 $20,000 $29,540,000 X1 28 Warehouse Building x x x 15 L/M $690,000 $0 $690,000 $2,739,000 X 19 Digester 9‐10 x x 12 M $0 $0 $0 $22,000,000 X1 29 Shop Building A x x 12 M $280,000 $0 $280,000 $1,956,000 X 3 Plant Water Pump Station & Power Building 6 x x x 10 M/H $420,000 $0 $420,000 $6,760,000 X‐0391 4 City Water Pump Station x x x 10 H $600,000 $860,000 $1,460,000 $5,030,000 X‐0381 7 Power Building 5 x x 10 H $250,000 $500,000 $750,000 $10,841,000 X 22 Digesters 11‐14 Pump Room x x x 10 M $1,080,000 $0 $1,080,000 $14,650,000 X1 23 Digesters 15‐16 Pump Room x x 10 M $420,000 $0 $420,000 $7,322,000 X1 25 Effluent Junction Box x x 10 L $0 $0 $0 $2,012,000 X1 33 PEDB2 x x 10 M $0 $680,000 $680,000 $4,585,000 X 6 Power Building 4 x x 8 M $220,000 $0 $220,000 $5,382,000 X 16 Digester 7 x x 7.2 M $0 $0 $0 $10,150,000 X1 18 Digester 8 x x 7.2 M $0 $0 $0 $10,150,000 X1 5 Power Building 2 xxxx 6 M $390,000 $2,000,000 $2,390,000 $6,236,000 X1 ? 14 Digester 5 & 6 Pump Room x x x 6 L/M $200,000 $920,000 $1,120,000 $6,764,000 X 17 Digester 7 & 8 Pump Room x x x 6 L/M $250,000 $0 $250,000 $6,764,000 X1 20 Digester 9‐10 Pump Room x x x 6 L/M $340,000 $0 $340,000 $7,322,000 X1 24 Gas Holder x x 2.4 M/H $140,000 $0 $140,000 $454,000 J‐124 ? 11 Aeration Basins 1‐10 x x x 0 NA $0 $0 $0 $219,336,000 X 13 Digester 5 x x 0 M $0 $0 $0 $10,150,000 X 15 Digester 6 x x 0 L $0 $0 $0 $10,150,000 X 27 Chiller Building x x x 0 NA $0 $0 $0 $682,000 X Notes:Subtotal $19,200,000 $4,800,000 $24,000,000 $1,021,000,000 1. Requires lateral spread mitigation. Total LS mitigation cost for Plant 1 is $33M.Global LS mitigation NA $33,000,000 $33,000,000 NA 2. Structure‐specific geotechnical mitigation costs exclude regional lateral spread mitigation.Total $19,200,000 $37,800,000 $57,000,000 $1,021,000,000 Controlling ConsequenceControl. Failure Recommendations (Draft)Cost Information PS15-06 TM4 Appendix C 684 Structure Number Structure Name GS DS LS Li f e S a f e t y Pr i m a r y Tr e a t m e n t Re g u l a t o r y St a k e h o l d e r Fi n a n c i a l Pu b l i c I m p a c t Overall RoSF Co n f i d e n c e Structural Mitigation Cost Geotechnical Mitigation Cost2 Total Mitigation Cost Facility Value No Project, LoSF = 0 Address with Previously Planned Project Mitigate with New Project Identified in TM3 Replace Facility 23 Surge Tower No. 1 x x 25 H $0 $0 $0 $18,300,000 X1 29 Ocean Outfall Booster Pump Station x x 25 M/H $1,660,000 $1,560,000 $3,220,000 $109,650,000 X1 27 Maintenance Building x x 25 M/H $3,430,000 $8,070,000 $11,500,000 $9,489,000 X 5 PEPS & MAC x x 20 M $0 $4,190,000 $4,190,000 $55,609,000 X‐0521 6 Operations/Control Center x x 20 H $2,000,000 $3,660,000 $5,660,000 $21,312,000 X‐008 7 12 kV Service Center x x 20 H $780,000 $1,630,000 $2,410,000 $42,100,000 X‐047 17 Central Power Generation Building x x 20 H $4,240,000 $0 $4,240,000 $330,240,000 P2‐119 18 Aeration Basins A‐H x x x 20 M $0 $20,120,000 $20,120,000 $222,436,000 X‐050 21 DAFTs A‐C x x 15 M $0 $2,490,000 $2,490,000 $16,332,531 X 22 DAFT D x x x 15 M $40,000 $970,000 $1,010,000 $3,629,451 X 24 Surge Tower No. 2 x x 15 M $0 $0 $0 $18,300,000 X1 20 Secondary Clarifiers A‐L x x x 12 H $0 $18,810,000 $18,810,000 $222,436,000 X‐051 9 Power Building C x x 10 M/H $280,000 $1,740,000 $2,020,000 $4,360,500 X ‐???1 10 Power Building D x x 10 H $670,000 $0 $670,000 $3,947,400 X 14 Headworks Power Bldg A x x 10 M $60,000 $1,410,000 $1,470,000 $5,062,500 X 30 12 kV Distribution Center A x x 10 H $670,000 $2,660,000 $3,330,000 $8,717,000 X‐???1 3 RAS PS East x x x 9.6 L/M $180,000 $1,310,000 $1,490,000 $27,804,000 X‐0521 4 RAS PS West x x x 9.6 L/M $180,000 $1,580,000 $1,760,000 $27,804,000 X‐052 1 DAFT A‐C Gallery x x 9 M $0 $3,190,000 $3,190,000 $5,444,177 X? 11 City Water Pump Station x x 8 M $740,000 $2,680,000 $3,420,000 $8,629,000 X‐036 13 12 kV Distribution Center D x x 8 M $0 $1,000,000 $1,000,000 $2,520,450 X ? 15 Headworks Power Bldg B x x 8 M $130,000 $1,620,000 $1,750,000 $5,062,500 X ? 16 Headworks Standby Power Building x x 8 M $130,000 $1,970,000 $2,100,000 $5,971,050 X ? 2 DAFT D Gallery and WSSPS x x 6 M $0 $0 $0 $3,629,451 X1 12 12 kV Distribution Center B x x 6 M $0 $2,710,000 $2,710,000 $9,685,900 X1 19 Gas Holder x x 2.4 H $50,000 $0 $50,000 $600,000 J‐124 8 Power Building B x x 0 NA $0 $0 $0 $5,062,500 X 26 Truck Loading x x 0 NA $0 $0 $0 $27,300,000 X 28 Boiler Building x x x 0 NA $0 $0 $0 $2,000,000 X Notes:Subtotal $15,200,000 $74,500,000 $89,800,000 $1,222,000,000 1. Requires lateral spread mitigation. Total LS mitigation cost for Plant 2 is $80M.Global LS mitigation NA $80,000,000 $80,000,000 NA Total LS mitigation cost for only Plant 2 structures included in study is $17M.Total $15,200,000 $154,500,000 $169,800,000 $1,222,000,000 2. Structure‐specific geotechnical mitigation costs exclude regional lateral spread mitigation. Control. Failure Controlling Consequence Plant 2 ‐ Risk Ranking Cost Information Recommendations (Draft) PS15-06 TM4 Appendix C 685 Orange County Sanitation District Orange County Sanitation District TM4 PROJECT RECOMMENDATIONS SEISMIC EVALUATION OF STRUCTURES AT PLANTS 1 & 2 JANUARY 9, 2019 PRESENTED BY: Geosyntec Team PS15-06 TM4 Appendix C 686 Orange County Sanitation District Agenda • Introductions/Safety Moment • TM4 Overview • Cost estimating process • Review of: • Risk rankings • Mitigation costs • Project recommendations 2 PS15-06 TM4 Appendix C 687 Orange County Sanitation District • Shake Alert LA – now available 3 Safety Moment – EQ Early Warning PS15-06 TM4 Appendix C 688 Orange County Sanitation District • How does it work? Potential to provide a few seconds of warning of damaging shaking 4 Safety Moment – EQ Early Warning PS15-06 TM4 Appendix C 689 Orange County Sanitation District • What are the benefits? Alerts to Take cover Shut down equipment Start back up systems 5 Safety Moment – EQ Early Warning PS15-06 TM4 Appendix C 690 Orange County Sanitation District Meeting Objectives 6 • Gather OCSD input on PS 15-06 Project Recommendations PS15-06 TM4 Appendix C 691 Orange County Sanitation District Role of TM4 in Overall Scope 7 • Seismic Risk Rankings (Likelihood and Consequence) • Cost Estimates for Mitigations • Seismic Project Recommendations • Presentation of Project Report PS15-06 TM4 Appendix C 692 Orange County Sanitation District Discussion of Costing Approach 8 • Review Spreadsheets • Discussion PS15-06 TM4 Appendix C 693 Orange County Sanitation District • RoSF = LoSF x CoSF RoSF – Risk of Seismic Failure LoSF – Likelihood of Seismic Failure CoSF – Consequence of Seismic Failure • Projects sorted from highest RoSF to lowest Seismic Vulnerabilities Risk Ranking 9 PS15-06 TM4 Appendix C 694 Orange County Sanitation District Discussion of Project Recommendations 10 • Risk rankings • Mitigation costs • Project recommendations PS15-06 TM4 Appendix C 695 Orange County Sanitation District Plant 1-Geotech Mitigation Recommendations 11 Secant Pile Wall – Lateral Spread Mitigation ~2,800 LF Cost ~ $33 million PS15-06 TM4 Appendix C 696 Orange County Sanitation District Plant 2-Geotech Mitigation Recommendations 12 Secant Pile Wall – Lateral Spread Mitigation ~6,700 LF Cost ~ $80 million PS15-06 TM4 Appendix C 697 Orange County Sanitation District Discussion Discussion 13 PS15-06 TM4 Appendix C 698 Orange County Sanitation District Thank You!Thank You! 14 PS15-06 TM4 Appendix C 699