Seismic Performance Improvement of a Plan-Asymmetric RC building Designed for Gravity Loads

Abstract—A mixed retrofitting intervention including both FRP wrapping and RC jacketing applied to selected columns was proposed and investigated by numerical analyses with the aim of improving the seismic performance of a four-storey plan-asymmetric RC building designed for gravity loads. Retrofitting was aimed at both reducing the torsional component of the seismic response and improving the local and global ductility of the building. A displacement-based procedure using nonlinear static pushover analyses was adopted to assess the seismic performance of the structure in the original configuration and to select the retrofitting intervention. Due to the asymmetry of the investigated structure, appropriate correction factors were computed in order to take into account the effects of torsion. Nonlinear dynamic analyses were carried out to verify the effectiveness of the retrofitting intervention strategy. Demand-to-Capacity Ratio (DCR) values were used to evaluate the damage level of columns and to identify the most critical columns affecting the seismic performance of the structure.