Site specific analysis was carried out for a deep stiff soil site located near Ahmedabad, India. The site predominantly consists of sandy clay and silty sand layer in the top 30m with Vs varying from 430 to 750m/s. It is followed by a high plastic stiff clay layer cemented with sand and gravel with unusually high Vs above 1000m/s. The study region surrounded by 13 major faults has experienced several major earthquakes including the disastrous Bhuj earthquake (Mw=7.7). The seismic hazard level at the site was estimated by deterministic approach and the East Cambay fault with Mw of 6.2 is found to be the controlling source capable of causing a surface PGA of 0.46g. 1D ground response analysis carried out using SHAKE 2000 and DEEPSOIL reveals an amplification of the ground with a surface PGA of 0.52g and 0.43g respectively. The design response spectrum obtained by RRS analysis was compared with several contemporary seismic design codes. It is found that the seismic provisions tend to under estimate the spectral acceleration by about 30% at mid period range. The maximum spectral acceleration compares well with those observed at similar deep stiff soil sites at Los Angeles reported by Chang et al (1997)
