Seismic resilience mechanism of self‐centering dual‐limb thin‐walled rocking piers with replaceable energy dissipation beams

Abstract

AbstractThis paper presents an innovative self‐centering dual‐limb thin‐walled rocking pier with replaceable energy dissipation beams (DLTW‐REDB), combining self‐centering hybrid system concepts with DLTW bridge piers. It addresses the issue of DLTW piers being prone to damage in the longitudinal direction during strong earthquakes, enabling rapid post‐earthquake recovery. The study focuses on the following aspects: (1) A 1:5 scale quasistatic reversed cyclic test was conducted to assess the seismic performance of the system. The results demonstrated that the hybrid system exhibited a characteristic “flag‐shaped” hysteretic response, similar to traditional rocking bridge piers. It exhibited excellent energy dissipation and self‐centering capability. Moreover, plastic damage primarily occurred in the replaceable energy dissipation beam, which could be easily replaced within 2 h while restoring the original structural behavior. (2) The self‐centering mechanism of the system was analyzed based on principles of structural mechanics, explicitly deriving the hysteresis, and residual deformation expressions. A quantitative index, the self‐centering coefficient (λ), was established to measure the self‐centering capability. (3) Numerical models were employed to analyze the sensitivity of parameters such as the prestressed reinforcement ratio, initial tension in prestressing tendons, and yield force of the energy dissipation beam. The results suggested that raising the initial tension enhanced the bearing force and reduced the residual displacement. However, raising the yield force improved the bearing capacity and energy dissipation capability, while residual displacement increased. Therefore, it is recommended to set the self‐centering coefficient at approximately 1.0 to achieve a trade‐off between effective energy dissipation capacity and acceptable residual deformation.