1202 W Edinger Ave - Plan - Laserfiche WebLink

Home Browse Search

Mater Dei High School October 20, 2023 Proposed Dance Studio, Santa Ana, California Project No. 3204.I 3204-I-01R (10/23) 5 4.2 SEISMIC CONSIDERATIONS 4.2.1 General The site is located in a seismically active area typical of Southern California and is likely to be subjected to strong ground shaking due to earthquakes on nearby faults. We assume the seismic design of the proposed development will be in accordance with the 2022 California Building Code (CBC) criteria. A Site Class D may be used for design in accordance with the 2022 CBC. Using the Site Class and the appropriate internet website (ASCE 7 Hazard Tool), the corresponding seismic design parameters from the CBC are as follows: 2022 CBC: SS = 1.29g SMS = Fa * SS = 1.29g SDS = 2/3 * SMS = 0.86g S1 = 0.46g SM1 = FV * S1 = 0.85g SD1 = 2/3 * SM1 = 0.56g Note: The Project Structural Engineer should confirm these values prior to their use. In accordance with the 2022 CBC, site-specific response spectra are required for structures located in a Site Class D (with S1 greater than or equal to 0.2), unless per the exceptions detailed in Section 11.4 8 of ASCE 7-16 (ASCE, 2016), the structure is designed using seismic response coefficient (Cs) determined by either: • Equation 12.8-2 for values of T ≤ 1.5 TS, • 1.5 times the value computed by Equation 12.8-3 for values of TL ≥ T > 1.5 TS, or • 1.5 times the value computed by Equation 12.8-4 for values of T > TL. If this exception is not taken and the structure will still be designed in accordance with the 2022 CBC, GPI should be notified that a site-specific response spectra is required. 4.2.2 Strong Ground Motion Potential During the life of the project, the site will likely be subject to strong ground motions due to earthquakes on nearby faults. Based on the appropriate websites, we computed that the site could be subjected to a peak ground acceleration (PGAM) of 0.60g (ASCE 7 Hazard Tool) for a mean magnitude 6.7 earthquake (USGS). This acceleration has been computed using the mapped Maximum Considered Geometric Mean peak ground acceleration from ASCE 7-16 (ASCE, 2016) and a site coefficient (FPGA) based on site class. The predominant earthquake magnitude was determined using a 2-percent probability of exceedance in a 50-year period, or an average return period of 2,475 years. The structural design will need to incorporate measures to mitigate the effects of strong ground motion. 1202 W Edinger Ave10/3/2024