Comprehensive amplification estimation of the Indo Gangetic Basin deep soil sites in the seismically active area

Site amplification coefficients and acceleration design response spectra (ADRS) for the deep Indo-Gangetic Basin (IGB) have been proposed. Non-linear site response analysis is carried out at 275 deep shear wave velocity (V-S) profiles by selecting the input motion based on seismic hazard map for 10% probability of exceedence in 50 years. The spatial variation map of peak ground acceleration (PGA) and spectral acceleration (SA) at surface and various depths for the JOB are also presented. The bedrock PGA of 0.03-0.24 g increased to 0.1-0.97 g at surface and 0.05-0.35 g at a depth of 150 m. Maximum SA is observed between 0.08 s and 0.5 sec. The new site factors viz. F-a and F-v are derived for newly defined spectral period range. Further, ADRS is constructed which depends on PGA and seismic site class as per NEHRP. Proposed ADRS is compared with different deep basin studies and BIS:1893.