Numerical Study on Seismic Performance of Rocking Self-Centering (RSC) Bridge Piers Under Bidirectional Excitation

Abstract

To study the seismic performance of rocking self-centering (RSC) bridge piers, a numerical model of RSC pier is established based on the OpenSees platform. The model is verified by experimental results. The seismic performance of RSC piers is analyzed under quasi-static and seismic loads, respectively, in terms of peak lateral drift, residual deformation, compressive zone height of the cross-section and tendon stress. Far-field, near-field without pulse and near-field pulse-like ground motion records are selected for the time-history analysis. The effects of prestressing tendon reinforcement ratio, energy-dissipating bar ratio and axial load are examined, respectively. The results show that the strength of the RSC pier, the depth of the compressive zone of the cross-section and the self-centering capacity increase with increasing prestressing tendon reinforcement ratio. When the energy-dissipating reinforcement ratio exceeds 1%, the boost of seismic performance of the pier becomes insignificant. The increasing axial load can increase the lateral strength of the pier. However, it could lead to premature yielding of the prestressing tendons.