This 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.

中文翻译：

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可更换耗能梁自定心双肢薄壁摇摆墩抗震机制

本文提出了一种创新的带可更换耗能梁的自定心双肢薄壁摇摆墩（DLTW-REDB），将自定心混合系统概念与 DLTW 桥墩相结合。它解决了DLTW桥墩在强震期间容易纵向损坏的问题，实现震后快速恢复。研究重点包括以下几个方面：（1）进行1：5比例的准静态反循环试验，评估系统的抗震性能。结果表明，混合系统表现出特征性的“旗形”迟滞响应，类似于传统的摇桥桥墩。它表现出优异的能量耗散和自定心能力。此外，塑性损伤主要发生在可更换耗能梁上，可在2小时内轻松更换，同时恢复原有的结构性能。(2)基于结构力学原理分析了系统的自定心机理，明确推导了迟滞和残余变形表达式。建立了衡量自定心能力的量化指标——自定心系数（λ）。(3)采用数值模型分析了预应力配筋率、预应力筋初拉力、耗能梁屈服力等参数的敏感性。结果表明，提高初始张力可增强承载力并减少残余位移。但屈服力的提高提高了承载能力和耗能能力，但残余位移增加。因此，建议将自定心系数设置为1.0左右，以实现有效耗能能力和可接受的残余变形之间的权衡。