3500 TERMINAL AVE Geotech Report 2022-10-25

Port of Everett—South Terminal Wharf& Electrical Upgrades—Phase 2 113 Analysis Results The results of our analyses,which are summarized in Tables 10 and 11, indicate that the critical factors of safety for the profiles studied exceed the standard of practice under static conditions(factor of safety of at least 1.5)and liquefied conditions (factor of safety of at least 1.05).The resulting factors of safety are presented in Tables 10 and 11 for Section A-A'and Section D-D', respectively. For section A-A',the current conditions show factors of safety below 1.1 for the pseudostatic analyses at hazard levels above the 144-year return period.The proposed Phase II upgrade design consistently meets or exceeds the current stability of each section for all considered earthquake events,as well as the current and post-earthquake liquefied soil static conditions,for Section A-A'. For Section D-D',the current conditions indicate pseudostatic instability for the design-level only, and static instability in the post-earthquake liquefied condition.The proposed Phase II pile upgrades result in factors of safety of greater than 1.1 for all static and pseudostatic conditions.The results of our slope stability analyses for static, pseudostatic, and liquefied conditions for both design scenarios are described further in detail in Appendix F. Table 10 - Factors of Safety Under Various Loading Scenarios for Profile A-A' Loading Scenario Existing Condition Phase II Upgrade Static 1.65 1.91 Pseudostatic 72-year Return Period 1.42 1.59 (k = 0.079) 94-year Return Period 1.24 1.56 (k = 0.091) 144-year Return Period 1.17 1.43 (k = 0.109) 224-year Return Period 1.08 1.59 (k = 0.122) 475-year Return Period 1.00 1.49 (k = 0.144) Design Earthquake 0.96 1.31 (k = 0.189) Post-seismic Liquefied 1.61 1.89 MN 11.111 19232-01 HARTCROwSCR December 6,2017