Deterministic seismic hazard analysis for Phuentsholing region of southern Bhutan considering local site effects

Abstract

Phuentsholing is a thriving border town in the southwestern part of Bhutan. With the development of infrastructure over time, the safety of the residence and lifeline buildings becomes a matter of concern. Bhutan lies in the Himalayan mountain ranges, which is considered one of the most active regions for seismic events. The Indian seismic code, IS 1893-2016, has assigned Zone IV for the region, which signifies the large risk that exists for all the structures. Therefore, conducting a seismic hazard assessment for the site becomes extremely necessary before any major construction. The present study focusses to perform the deterministic seismic hazard analysis (DSHA) around certain points of interest in the town of Phuentsholing, in Bhutan. Furthermore, site-specific response spectra for Pipaldhara-1, Pipaldhara-2, Kabreytar-1, Kabreytar-2 and Phuentsholing town were plotted from the results of the DSHA. It is estimated that a peak ground acceleration ranging from 0.11 to 0.14 g can be anticipated at the level of bedrock in the study region. Response spectra were plotted for the ground level using appropriate soil-amplification coefficients, derived from the analyses in the DEEPSOIL program. © 2022, Springer Nature Switzerland AG.