effect of multi-direction analysis on the fragility curves of regular rc buildings

Recently, fragility functions are used to study the vulnerability of structures. currently, the analytical fragility functions are developed by two-dimensional analysis of structures, and the effect of three earthquake component and three-dimensional analysis is neglected. however, some studies have been conducted to develop fragility function of thestructure by 3d analysis. presumably, three-dimensional analysis of structures was required for the asymmetric and irregular structures, and symmetric structures are exempt from that. however, even in a perfectly symmetric structure, the difference between the earthquake components may cause differences between each direction. xu et al. compared thefragility function of asymmetric structure which developed by 2d and 3d analysis and showed that the using 2d analysis underestimated the results. in this study, to investigate the effect of 3d analysis on the fragility function of structures, three perfectly symmetrical reinforced concrete structures with moment resisting frame system were investigated in thefar-field of the earthquake. the result is then compared with the corresponding fragility curves developed by the twodimensional analysis.