Shaking table test study on seismic performance of UHPC rectangular hollow bridge pier

Abstract To study the seismic failure mode and dynamic response characteristics of ultra-high performance concrete (UHPC) rectangular hollow bridge pier under dynamic loads, the El Centro wave, Taft wave, and Northridge wave were selected as seismic excitation for the shaking table test. The responses such as natural frequency, damping ratio , acceleration-time and displacement–time curves were investigated and the results were compared with the finite element simulation results. At the same time, 8 finite element models (FEMs) of UHPC rectangular hollow bridge pier were established to explore the influence of longitudinal reinforcement ratio and stirrup ratio on the seismic performance of bridge piers. The results indicated that with the increase of peak ground acceleration (PGA), the damping ratio, acceleration, displacement and UHPC strain of the specimen increased, while the natural frequency and the dynamic amplification factor of the pier decreased gradually due to the accumulation of damage. The increase of longitudinal reinforcement ratio improves the ductility, and the increase of stirrup ratio enhances the constraint effect of core UHPC and ductility to a great extent, which leads to different acceleration, displacement and equivalent plastic strain response of bridge piers. On the whole, the stiffness of UHPC rectangular hollow bridge pier was degraded after the input of seismic wave , but the ultimate bearing capacity was not deteriorated. The overall seismic performance is superior. In areas with low seismic fortification intensity, the reinforcement ratio of UHPC rectangular hollow bridge piers can be appropriately reduced.