Seismic assessment of multi-storey residential building using fragility curve and capacity demand response spectrum

Abstract

Malaysia mostly experiences long-distance tremors caused by earthquake events from nearby countries. The majority of low-rise to medium-rise residential reinforced concrete buildings in Malaysia are designed with inadequate reinforcement detailing to cater for lateral loading. This paper presents findings related to seismic assessment of multi- storey residential buildings using the fragility curve and capacity-demand response spectrum. The main objective of this paper is to evaluate the vulnerability of residential multi-storey buildings with strong beam and weak column designed mechanisms subjected to Design Basis Earthquake and Maximum Considered Earthquake with peak ground acceleration of 0.12g and 0.22g, respectively. Ruaumoko2D programme was used to determine the load and displacement values of the building subjected to the 2015 Ranau earthquake with PGA 0.14g. The ductility of the prototype building was calculated from the load and displacement graph. The value of ductility was used to develop the fragility curve based on damage state characterization in accordance to FEMA273. The findings from the fragility curve show that the building would experience minor to moderate damage and can be repaired or retrofitted after the earthquake events with peak ground acceleration of 0.12g and 0.22g. This study also presents the result of the capacity-demand response spectrum of the building subjected to Design Basis Earthquake and Maximum Considered Earthquake in accordance with Eurocode 8 specifications. The result from the capacity demand response spectrum shows that the building would not survive when subjected to the earthquake excitation with peak ground acceleration 0.22g and exceeds more than 5.5 Richter Scale. This study is important to provide an understanding of the seismic behaviour of the multi-storey non-seismic designed for residential buildings in Malaysia.