Seismic Vulnerability Assessment of Existing Building Stocks at Chandgaon in Chittagong City, Bangladesh

Abstract

The draft of Bangladesh National Building Code (BNBC)-2012 has been updated the seismic coefficient of 0.28g (with Zone III) for Chittagong region, which is larger than the previous of 0.15g (with Zone II). Chittagong is the largest port city and commercial capital of Bangladesh, which has many development activities as like of planned residential areas. Although BNBC code is up-to-date with earthquake provisions since 1993 with interpreting several new clauses and provisions, but in case of pre-code revision structures it is quite unsafe. Thus it is quite impossible to reduce earthquake damage without considering the safety of pre-code revision structures. In this regards earthquake vulnerability of Chandgaon Residential Area(R/A) has been assessed on the basis of potential structural vulnerability of more than 300 buildings. Initial results reveal that there have large varieties of construction practices, however, predominantly RCC structures were found. RVS score of these structures reveal that in general buildings are of minimum quality and further evaluation and strengthening of buildings is recommended. Walk down evaluation encountered several factors which were responsible for comparatively lower range of vulnerability scores.