Multi-objective design model for retrofit of reinforced concrete frames with infilled walls using FRP bracings

Since existing structures can be retrofitted without removing or damaging the existing structural members, a seismic retrofit with FRP bracings has high applicability and cost efficiency. This study proposes an FRP-bracing-based optimal seismic retrofit method for reinforced concrete (RC) frames with infill walls. This method minimizes the number of FRP bracings for the retrofit and maximizes the dissipated energy while satisfying constraints related to interstory drift and structural collapse. The proposed method is applied to 5- and 10-story reinforced concrete frames, and optimal retrofit schemes that suggest the locations and number of FRP bracings are obtained. To support the decision-making of the building owner and engineer, the representative retrofit plans are selected and analyzed. It is shown that a reinforced structure with the optimal solution shows improved results in terms of both strength and deformation capacity.