Seismic Fragility Evaluation of SCCB-Enhanced RC Frame Structures

Abstract

A novel self-centering cable brace (SCCB) with friction devices was developed to improve the seismic performance of existing frame structures. To investigate the enhancing effect of the SCCB on reinforced concrete (RC) frame structures, seismic fragility evaluation of SCCB-enhanced RC frame structures was conducted based on the incremental dynamic analysis (IDA), through which probabilities of exceedance at various performance limit states are calculated. The proposed evaluation procedure was applied to a seismically deficient six-story RC frame, where buckling-restrained braces (BRBs) and SCCBs with similar damping properties were used and compared for strengthening effects. According to the IDA results, the seismic fragility curves of the two strengthening schemes were obtained. Compared with the BRB-enhanced frame, the SCCB-enhanced frame exhibits significantly better seismic capability under rare earthquakes. In addition, lower probability of exceedance is observed in the SCCB-enhanced frame under the repair available state, indicating that the SCCB-enhanced RC frame is more seismic resilient than the BRB-enhanced frame.