Site-Specific Seismic Ground Response for Mormugao Port, Goa, India: Fid-Bau Portal

Site-Specific Seismic Ground Response for Mormugao Port, Goa, India

Bhingarde, Nika S. / Naik, Nisha P.

Ports are lifeline structures, which play an important role in the economic growth of any country. Hence these structures should necessarily be designed for earthquakes. Mormugao Port in the south west region of Goa State, which lies on the west coast of India is located at about 250 km from Koyna and 350 km from Latur which, in the past have experienced earthquakes of magnitude M_w=6.3 and M_w=6.2 respectively. In this paper, seismic ground response study is carried out for Mormugao Port of Goa State. Data of ten borelogs were obtained from the port site. The bedrock depth was found to vary from 10.50 to 16.50 m. The shear wave velocity (V_s) was evaluated using two established correlations developed between V_s and field SPT ‘N’. Earthquake time histories were developed for the port site using three methods: (i) generating synthetic accelerograms, (ii) generating artificial accelerograms, both by using SeismoArtif 2.1.0 software, and by (iii) matching the Indian seismic codal bedrock target spectra using SeismoMatch 2.1.0 software, by considering seed accelerograms of real earthquakes. One dimensional equivalent linear ground response analysis was carried out using DEEPSOIL v6.0 software using generated accelerograms. The influence of local soils on the bedrock motion (for 8 time histories) was represented in the form of surface acceleration time history, amplification spectra, response spectra, and ground motion parameters. The site at the Mormugao Port was found to be amplifying type with a maximum amplification (Fourier amplitude) of 12.69.