Seismic Retrofit of Framed Buildings Using Self-Centering PC Frames

In this study, self-centering post-tensioned precast concrete (PC) frames are developed for seismic retrofit of reinforced concrete (RC) framed structures. The cyclic loading test of a RC frame retrofitted with a SC-PC frame is carried out to evaluate the effectiveness of the seismic retrofit. SC-PC frames are applied analytically for the seismic retrofit of three different reinforced concrete model structures using a simple design procedure based on the capacity spectrum method. The effectiveness of the retrofit scheme is investigated through nonlinear time-history response analysis (NLTHA), incremental dynamic analysis (IDA), and seismic fragility analysis. The analysis results indicate that the SC-PC frames are effective in reducing the maximum interstory drift ratio (MIDR) and eliminating the residual drift of the model structures. In addition, the proposed retrofit scheme is effective in increasing the median collapse capacities and decreasing the probabilities of reaching the design limit states of the RC structures. (C) 2020 American Society of Civil Engineers.