Investigation on the seismic retrofit positions of FRP jackets for RC frames using multi-objective optimization

This research aims to achieve an optimal seismic retrofit method using fiber reinforced polymer (FRP) jackets and to investigate the distributions of retrofit positions and the amount of FRP using the solutions obtained by the proposed method. This method utilizes two objective functions. The first minimizes the amount of FRP reinforcement for economic feasibility, and the second maximizes the spectral acceleration of ground motion that causes the collapse of a structure to reduce the collapse risk. The proposed method is tested on a 3-story reinforced concrete (RC) frame example structure. The amount of FRP used in schemes to retrofit only columns is less than the amount used in schemes to retrofit both columns and beams. In addition, retrofit schemes to differentiate the retrofit level according to the retrofit position are proposed as optimal solutions.