Seismic Performance of a Novel Self‐Centering Railway Bridge Pier Equipped With Disc‐Spring Assemblies and Rubber Pads

ABSTRACT The railway piers characterized by low reinforcement ratio are particularly susceptible to concentrated cracking at the base during seismic events, which considerably complicates post‐earthquake repair. Self‐centering piers, incorporating prestressed tendons and energy‐dissipating steel bars, encounter three primary challenges: the difficulty of applying vertical prestress, the continual loss of prestress during service, and the complexities associated with the post‐earthquake replacement of energy‐dissipating bars. This study proposes an innovative self‐centering railway pier design utilizing disc‐spring assemblies instead of traditional prestressed tendons, along with cost‐effective rubber pads for friction energy dissipation. The experimental results indicate that conventional ductile piers sustain substantial damage at the bottom, whereas the self‐centering piers remain unscathed. Although the self‐centering piers exhibit reduced load‐carrying capacity and energy dissipation, they demonstrate minimal residual displacement and commendable self‐centering performance. Enhancing the preload torque of the rubber pads and the width of the enlarged footing improves both the load‐carrying and energy dissipation capacities of the self‐centering piers. However, increased preload torque leads to greater residual displacement, while enhancing the stiffness of the disc‐spring assemblies contributes to improved post‐yield stiffness. By regulating three normalized design parameters, namely the initial stiffness ratio of disc‐spring assemblies to the pier, the ratio of enlarged footing width parallel to the loading direction to the height of the pier, and the ratio of the frictional force of the rubber pad to the uplifting force of the pier, the proposed self‐centering pier can achieve load‐carrying and energy dissipation capacities comparable to conventional ductile piers while maintaining negligible residual displacements.