Development of the Fragility Curves for Conventional Reinforced Concrete Moment Resistant Frame Structures in Qods Town, Qom City, Iran

Abstract

In the Second World Conference on Disaster Risk Reduction (WCDRR) the concept of resilience has been presented as an Effective Strategy to improve post-earthquake conditions. One of the principles of resilience is “quick response”, which requires having relevant information to determine the level of vulnerability of the city. For this purpose, many studies have been done in recent years to investigate the seismic behavior of a variety of infrastructures in a city. The fragility curve is one of the most popular tools among researchers to investigate the probabilistic seismic behavior of structures. It expresses the degree of structural vulnerability by indicating the exceedance probability of damage versus the given level of ground shaking. In this study, 24 fragility curves are developed for four typical intermediate Reinforced Concrete Moment Resistant Frame structures in Qods town (located in Qom, Iran) with two number of stories (4 and 8) and two number of bays (1 and 2). They are derived through nonlinear incremental dynamic analysis in one and two horizontal directions under two sets of near-field and far-field ground motion records. The results indicate that the seismic response of structures is the same for uni-directional and bi-directional analyses. Also, it seems that the response of the structures with periods greater than 1 sec is in correlation with the mass-to-stiffness ratio. Change in the width and number of bays of the structure does not affect the probability of failure, as far as the width to the number of bays ratio remains constant. Furthermore, the probability of failure is higher when the structure is subjected to near-field earthquake ground motion records.

Keywords

• damage evaluation
• fragility curve
• incremental dynamic analysis
• reinforced concrete moment resistant frame
• sap2000