Design Spectral Acceleration (DSA) values at damping other than 5 percent shall be obtained by using a procedure given in Chapter 1 of FEMA 356 [3.1], and is denoted as DSAd. The following procedure does not include near-fault directivity effects.
|BS||=||Coefficient used to adjust the short period spectral response, for the effect of viscous damping.|
|B1||=||Coefficient used to adjust one-second period spectral response, for the effect of viscous damping|
Values of BS and B1 are obtained from Table 31F-3-5.
Such a procedure shall incorporate the near-fault directivity effects when the MOT is 15 km (9.3 miles) or closer to a significant seismic source.