考虑支座及挡块力学性能退化的桥梁横向地震响应分析

摘要

板式橡胶支座的摩擦滑移特性及横向挡块力学性能是影响中小跨径梁桥横向抗震性能评价的重要因素.通过循环水平加载试验,考虑橡胶材料、竖向压应力及加载速率等参数,探讨了板式橡胶支座摩擦滑移特性及滑移后力学性能;在此基础上,对一座三跨预应力混凝土连续梁桥模型进行动力增量分析,分析了板式橡胶支座的滑移损伤及挡块力学性能退化对横桥向地震响应的影响.结果表明:循环水平荷载作用下的板式橡胶支座会因摩擦滑移而发生一定损伤,不同影响因素下损伤情况不同,但其摩擦滑移特性均会逐渐趋于稳定;板式橡胶支座摩擦滑移损伤及挡块的力学性能退化对横桥向地震响应影响较大,且其相互影响,在中小跨径梁桥抗震分析中应同时考虑.%The friction sliding feature of laminated rubber bearings and the mechanical performance of stoppers have significant influences on the transverse aseismic ability evaluation of medium-small span bridges.A cyclic loading test was conducted to investigate the friction sliding feature and the mechanical performance of laminated rubber bearings after sliding,the effects of relevant parameters,such as,vertical compressive stress,loading rate and rubber material were considered.The FE model of a three-span prestressed concrete continuous beambridge was built and its transverse seismic responses were studied with the incremental dynamic analysis method considering performance degradation of bearings and stoppers.The results showed that laminated rubber bearings have a certain damage due to friction and sliding under the action of horizontal cyclic loads;their damage levels are different under different affecting factors,but their friction sliding feature can tend to a stable state gradually;friction sliding damage of bearings and stoppers' performance degradation have significant influences on the transverse seismic responses of bridges,they interact each other,so the performance degradation of bearings and stoppers should be considered in aseismic analysis of medium-small span bridges.