Seismic performance enhancement of precast bridge pier using ultrahigh-performance concrete jacket

The application of precast bridge piers is becoming increasingly widespread due to its significant time-saving advantages. To enhance the seismic performance of the bridge piers, ultrahigh-performance concrete (UHPC) jackets was set in the plastic hinge of the precast bridge piers with socket connection. Quasi-static tests were conducted on five specimens to investigate the influence of the height and thickness of the UHPC jacket on the seismic behavior of precast bridge piers. When the UHPC jacket height was too low or the thickness was too great, the plastic hinge region of the pier shifted upward, reducing the ductility and cumulative energy dissipation of the pier, which adversely affected its seismic performance. Based on the numerical analysis results, a bending moment enhancement coefficient was regressed and the dimension design method of UHPC jacket was proposed. This study provides a reference for designing UHPC jackets to enhance the seismic performance of bridge piers.