Buildings' seismic vulnerability assessment methods: a comparative study

A critical review and comparison of existing seismic vulnerability assessment techniques for buildings are carried out to evaluate their suitability for use in seismic risk assessment. The methods considered are "Hybrid" vulnerability assessment method, FEMA 154 (Rapid Visual Screening), Euro Code 8, New Zealand Guidelines, Modified Turkish method and NRC Guidelines. A scoring system is proposed to select the suitable vulnerability assessment technique to be utilized for three different case studies conducted in different seismicity and geological zones, that is, Dhaka, and Rangamati cities, in Bangladesh, and Kelowna, in Canada. The ranking considers general description of vulnerability, building response factors, variance in output, applicability and ease of use, which are identified as the key characteristics required for vulnerability scales used in seismic risk evaluation. A sensitivity analysis has been carried out for the different methods with regard to different weighting criteria. Furthermore, a multi-criteria decision-making tool AHP has also been utilized to find out the suitable alternatives for seismic vulnerability assessment of buildings. It was observed that the Hybrid method adequately satisfies all the criteria necessary for their use in seismic risk assessment. Vulnerability maps of different study areas using Hybrid method have been integrated into a GIS framework to visualize the building vulnerabilities in a spatial manner, which will facilitate the authority to manage effective seismic hazard risk reduction measures, including upgrading, repairing and retrofitting of structures.