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Mr. Dan Yoon 5150.100.001 Hana Japan Steak House January 23, 2023 2022 CBC SEISMIC DESIGN PARAMETERS UPDATE Latest Revision November 3, 2023 Page 2 In the following Table 1, we provide the 2022 CBC seismic parameters based on the United States Geological Survey’s (USGS’s) Seismic Design Maps for your use. When using this table, considerations should be given to exceptions in Section 11.4.8 of ASCE 7-16, as described in this report. TABLE 1: 2022 CBC Seismic Design Parameters, Latitude: 37.69444, Longitude: -121.93483 PARAMETER VALUE Site Class D Mapped MCER Spectral Response Acceleration at Short Periods, SS (g) 1.98 Mapped MCER Spectral Response Acceleration at 1-second Period, S1 (g) 0.73 Site Coefficient, Fa 1.2 Site Coefficient, Fv 1.7* MCER Spectral Response Acceleration at Short Periods, SMS (g) 2.38 MCER Spectral Response Acceleration at 1-second Period, SM1 (g) 1.24* Design Spectral Response Acceleration at Short Periods, SDS (g) 1.59 Design Spectral Response Acceleration at 1-second Period, SD1 (g) 0.83* Long period transition-period, TL (sec) 8 *The parameters above should only be used for calculation of Ts, determination of Seismic Design Category, and, when taking the exceptions under Items 1 and 2 of ASCE 7 -16 Section 11.4.8. (Supplement Number 3 https://ascelibrary.org/doi/epdf/10.1061/9780784414248.sup3 ). The design parameters remain valid from the previous 2019 CBC to the new 2022 CBC. Since the seismic design methodology did not change, the building can still be designed under either building code. Recommendations in the original report are still valid for this project. In addition, Comment 4.b. of Reference 3 states: “Section 5.4.4 “Seismically Induced Landsliding” indicates that an existing driveway and 25-foot setback will provide a debris catchment area in the event of seismically induced landsliding. This area will be significantly altered by grading and the installation of tiered retaining walls with combined heights up to 15’. The geotechnical engineer shall indicate whether the retaining walls will be designed to support additional surcharge loading from landslide debris, and/or whether the intent is for landslide debris to flow over the walls and accumulate on the new driveway below the walls. Note that Figure 2 of the report shows Cross-Section A-A through this area, yet the relationship between the landslide, set-back, and debris catchment, as well as the tiered retaining walls, new driveway, and exterior building wall are not accurately shown.” Due to changes in the Building Code since the time our geotechnical report was published, we recommend that walls taller than 6 feet in height be designed for seismic loading; the active incremental seismic force along the face of a retaining wall should be added to the static active pressures and can be calculated as follows. ΔP = 18 x H2 (level backfill slope)