Seismic collapse safety of RC circular bridge pier retrofitted with fibre reinforced polymer

In recent years, the use of fibre reinforced polymer (FRP) composites sheets used to enhance the lateral confinement for improved ductility and strength of reinforced concrete (RC) bridge piers. The collapses of bridge structures in past and recent seismic events have raised concerns regarding the adequacy of lateral confinement of existing bridges to prevent the partial or total collapse. This research deals the seismic collapse safety of existing RC bridge piers retrofitted with FRP and compares with existing old RC bridge piers designed without consideration of seismic design guidelines. The collapse safety performance of FRP retrofitted RC bridge pier was evaluated using 20 different ground motions to compare the performance of FRP retrofitting system. Using incremental dynamic time history analysis, the collapse risk of the FRP retrofitted bridge piers was evaluated considering uncertainties in ground motion characteristic and structural modelling. The outcome of the research will provide an estimate of the dynamic capacity of the FRP retrofitted bridge piers and demonstrate the effectiveness of FRP-retrofitting technique as an external reinforcement.