Earthquake information data.

This study builds a special numerical model based on the OpenSees platform, aiming to explore the influence of structural separation on the damage of bridge piers under excitation. The key parameters and threshold conditions related to structural separation were clarified by using simple harmonic excitation. The validity of the established theoretical framework was verified through multiple actual seismic waves, as well as the effect of vertical separation of piers and beams on damage development. At the same time, the damage differences of piers at different heights were compared in combination with vulnerability analysis, with a focus on the regulatory effect of separation on pier failure. The research results show that there is a significant correlation between the excitation parameters and the structural response. Especially when the seismic period approaches the first-order vertical natural vibration period of the bridge, the maximum axial pressure of the bearing increases exponentially with the amplitude, and after the separation occurs, the sensitivity of the collision force to the amplitude is significantly reduced. The working state of bridge piers is significantly affected by seismic waves and the connection form of the bearing type, which leads to regular changes in the structural safety state and failure mode due to the differences in seismic wave characteristics. Meanwhile, the height of the bridge pier plays a key role in the structural response. As the height of the bridge pier increases, the maximum contact force shows a downward trend. However, the vertical separation of the pier and the beam is more likely to cause severe damage or even complete failure of the bridge pier. The above research conclusions provide theoretical references of practical significance for strengthening the seismic design of Bridges.本研究基于OpenSees平台构建专用数值模型，旨在探究地震激励下结构分离对桥墩损伤的影响。通过简谐激励明确了与结构分离相关的关键参数与阈值条件。通过多组实际地震波验证了所构建理论框架的有效性，同时验证了墩梁竖向分离对损伤发展的影响。结合易损性分析对比了不同高度桥墩的损伤差异，重点关注结构分离对桥墩破坏的调控作用。研究结果表明，激励参数与结构响应间存在显著相关性。尤其当地震周期接近桥梁的一阶竖向自振周期时，支座最大轴压力随幅值呈指数增长；而在发生分离后，碰撞力对幅值的敏感度显著降低。桥墩的工作状态受地震波与支座连接形式的显著影响，进而因地震波特性差异导致结构安全状态与破坏模式呈现规律性变化。与此同时，桥墩高度对结构响应起到关键作用：随着桥墩高度升高，最大接触力呈下降趋势；但墩梁竖向分离更易引发桥墩严重损伤乃至完全失效。上述研究结论可为桥梁抗震设计优化提供具有实际应用价值的理论参考。