防落梁装置与铅芯橡胶支座耦合分析

Coupling analysis on unseating prevention device and lead rubber bearing

针对应用铅芯橡胶支座的桥梁存在落梁风险的问题,提出采用防落梁装置控制地震位移的方法。以某连续梁桥为例,采用非线性动力时程分析方法对防落梁装置和铅芯橡胶支座进行耦合分析,并对防落梁装置参数进行优化。结果表明:防落梁装置可以有效控制铅芯橡胶支座在地震作用下的变形,避免了支座破坏,降低了落梁风险;防落梁装置会引起桥墩地震内力的增加,设计时应引起足够重视;初始间隙和抗压刚度是防落梁装置的主要参数,其中初始间隙根据支座设计位移选取,抗压刚度根据支座位移与桥墩受力共同确定。

A seismic displacement control method based on unseating prevention device(UPD) is proposed to solve the problem of beam-falling risk in bridge with lead rubber bearing(LRB). Taking a continuous beam bridge as an example, the nonlinear dynamic time-history analysis method is adopted to analyze UPD and LRB, and the parameters of UPD are optimized. The results indicate that UPD could effectively reduce the seismic displacement of LRB, which could avoid bearing damage and reduce the risk of beam-falling;UPD would increase the seismic force of pier, which should be pay special attention;initial gap and compressive stiffness are the main parameters of UPD, where the former could be chosen by the design displacement of LRB, and the later could be chosen by the design displacement of LRB and the seismic force of pier.