Hysteretic performance of RC double-column bridge piers with self-centering buckling-restrained braces

Bridges are lifeline structures. The large residual displacement of a bridge structure after a severe earthquake can significantly impede the post-quake rescue activities. The self-centering buckling-restrained brace (SC-BRB) consisting of a self-centering (SC) component and a traditional buckling-restrained brace (BRB) is installed on the reinforced concrete (RC) double-column bridge piers to minimize the residual deformation of the bridge pier in the present study. The hysteretic behavior of the SC-BRB is experimentally investigated firstly, and compared with those of a traditional BRB and a self-centering brace (SCB). SC-BRB, BRB and SCB are then installed onto the RC double-column bridge piers, and large-scale quasi-static cyclic loading tests are performed to evaluate the hysteretic performances of these bridge piers. For comparison, the bridge pier without any brace is also tested. The damage patterns, hysteretic responses, residual displacements and energy dissipation capacities of the piers without and with different braces are analyzed and compared systematically. Experimental results demonstrate the obvious advantages of SC-BRB in increasing the strength and minimizing the residual deformation of the bridge column. Finally, a simplified hysteretic restoring force model for evaluating the hysteretic behavior of the pier with SC-BRB is developed for easy use. The comparisons between the analytical results and experimental data demonstrate the accuracy of the analytical model.