1615.2.5 Design spectral response coefficients

Where the site-specific procedure is used to determine the design ground motion in accordance with Section 16 15.2.4, the parameter SDS shall be taken as the spectral acceleration, S_a, obtained from the site-specific spectra at a period of 0.2 second, except that it shall not be taken as less than 90 percent of the peak spectral acceleration, S_a, at any period. The parameter_SDI shall be taken as the greater of the spectral acceleration, Sa, at a period of 1 second or two times the spectral acceleration,Sa, at a period of 2 seconds. The parameters _SMS^and_SMI shall be taken as 1.5 times _SDSand S_DI, respectively. The values so obtained shall not be taken as less than 80 percent of the values obtained from the general procedures of Section 1615.1.