某大跨度钢桁架桥抗震分析

Seismic Analysis of A Large-span Steel Truss Bridge

大跨度多功能的地标性桥梁建筑在城市桥梁建设中频繁出现,其抗震性能的分析计算成为控制设计的主要因素,传统的桥梁结构的抗震设计不考虑固定支座破坏的非线性力学性能,但该假定是不切合工程实际的。以某大跨度钢桁架桥为例,采用MIDAS CIVIL有限元软件,分别采用地震反应谱和非线性时程分析方法,对考虑固定支座破坏与否的情况下桥梁结构的地震反应进行了对比分析,分析表明,考虑支座破坏分析后桥墩水平地震力大大减小,上部钢桁架与桥墩均未屈服,摩擦摆支座位移符合规范要求,非线性时程分析结果更符合工程实际。

In the urban bridge construction, the multifunctional large span bridges have appeared as the landmarks frequently. The analysis of bridge seismic performance has become a major factor in de- signing. The assumption of the tradition bridge design ignoring the nonlinear ability of the bearing de- struction is not realistic. Spectrum analysis and the time-history analysis for the large-span steel truss bridge is done and the stress of the upper steel truss has been checked in this paper by MIDAS CIVIL. The structure response has been compared before and after the destruction of the FPS bearing. Accord- ing to the analysis, the response force of the pier has been largely decreased which is considered the bearing destruction. Seismic design such as seismic bearings is effective and the seismic responses of both piers and truss are much more reduced and the nonlinear analysis is more reliable .