Assessment of Seismic Performance of Earthquake-Damaged RC Frame Structure Considering the Joint Effect of Maximum Drift and Post-Earthquake Residual Drift

Evaluating the seismic performance of earthquake-damaged structures (EDSs) is a significant step in determining the appropriate measures for rehabilitating structures after an earthquake. However, the effect of the lengthening of the structural period on the vulnerability of EDS is rarely taken into account. Furthermore, the joint effect of the maximum inter-story drift ratio (MIDR) and maximum residual inter-story drift ratio (MRIDR) on the seismic performance of EDS has not been investigated in previous studies. This study intends to fill this research gap. In this paper, totally 70 earthquake-damaged structure models (EDSMs) with various MIDR levels are established to represent the EDSs with various damage states. By employing EDSM to compute the vulnerability of EDS, it is possible to save a substantial amount of time while ensuring the accuracy of the vulnerability assessment. A performance reduction index (PRI) is proposed to quantitatively evaluate the increase in the vulnerability of EDS. The contributions of the degradation of component properties and the lengthening of the structural period in the reduction in the seismic performance of EDS are estimated. The results show that the effect of the lengthening of the structure period on the seismic performance of EDS cannot be overlooked in the case of evaluating the vulnerability of EDS. The relationship between the PRI, MIDR, and MRIDR is determined by bivariate linear regression analysis. The reduction in the seismic performance with respect to four performance levels is accurately estimated by considering the joint effect of MIDR and MRIDR, emphasizing the need to consider both MIDR and MRIDR when evaluating the seismic performance of EDS.