简支梁桥地震损伤演变过程分析及抗震设计建议

Analysis of Seismic Damage Evolution Process of Simply Supported Girder Bridge and Suggestions for Seismic Design

简支梁桥是我国使用最广泛的桥型,为明确其地震损伤演变过程,以典型的3跨简支梁桥为研究对象,采用OpenSees软件建立了精细化的有限元模型,并基于增量动力分析(IDA)方法进行了非线性时程分析。结果表明:板式橡胶支座和混凝土挡块是整个结构中最先发生损伤且损伤最严重的构件,桥墩损伤较轻,这一结论与近年来地震中采用板式橡胶支座的桥梁震害基本一致;连续梁桥震害与简支梁桥震害相近,但因连续梁桥上部结构质量较大,碰撞效应较明显;支座摩擦系数对桥梁上下部结构地震响应影响较大,为使桥梁整体损伤较小,可通过设计合理的支座,改变其支承接触面间的摩擦特性。

Simply supported beam bridge is the most widely used bridge type in China.In order to clarify its seismic damage evolution process,a typical three-span simply supported beam bridge is taken as the research object,a refined finite element model is built using OpenSees software,and nonlinear time history analysis is carried out based on incremental dynamic analysis(IDA)method.The results show that plate rubber bearing and concrete retaining block are the first and most severely damaged members in the whole structure,and the pier is less damaged,which is basically consistent with the seismic damage of bridges with plate rubber bearing in recent years.The seismic damage of continuous beam bridge is similar to that of simply supported beam bridge,but the impact effect is obvious because the superstructure of continuous beam bridge is large.The friction coefficient of bearing has a great influence on the seismic response of bridge structure.In order to reduce the overall damage of bridge,the friction characteristics of supporting contact surfaces can be changed by designing reasonable bearing.