可液化场地大跨度桥梁地震响应分析

发布时间：2019-01-30 20:36

【摘要】：在近年来的几次较大地震中,大量的桥梁结构遭到破坏,桥梁结构的抗震安全问题越来越受到人们的重视。地震灾害调查表明：除了地震等级外,桥梁结构所处的场地条件也是影响桥梁结构安全的重要因素之一,对处于可液化场地的桥梁进行抗震分析已经成为一个重要的工程问题。论文针对处于可液化场地的某铁路三跨连续梁-拱组合桥梁,为了考察桩-土相互作用及桩基土液化对结构地震响应的影响,利用ANSYS有限元计算软件,分别建立基于m值法和基于P-Y曲线法的全桩模型Ⅱ和模型Ⅲ,墩底固结模型Ⅰ。并使用ANSYS有限元软件,对各个模型进行振动特性计算分析、地震反应谱和时程计算分析。通过模型Ⅰ和模型Ⅱ对比分析了桩-土相互作用对桥梁振动特性的影响和地震响应的影响。通过模型Ⅱ和模型Ⅲ对比分析了液化土及其非线性对桥梁结构地震响应的影响。结合对结构地震响应的分析总结,指出了该桥的抗震薄弱环节。计算结果表明：3个有限元模型的基本振型相同,面外横向侧弯为该桥的基本振型。全桩模型Ⅱ和Ⅲ前5振型分布特点一致,表明模型对比分析方式和P-Y曲线法应用的合理性。模型Ⅰ、Ⅱ和Ⅲ的一阶频率分别为0.83669、0.51895、0.50278,考虑桩-液化土相互作用后,结构频率降低。拱顶横向位移反应谱计算值分别为0.00518m、0.0211m和0.0216m,时程计算值分别为0.00513m、0.0203m和0.0221m,考虑桩-土相互作用及液化土非线性后,结构关键位置位移响应值进一步增大。
[Abstract]:In recent years, a large number of bridge structures have been damaged in several major earthquakes, and people pay more and more attention to the seismic safety of bridge structures. The investigation of earthquake disaster shows that the site condition of bridge structure is also one of the important factors that affect the safety of bridge structure, besides the earthquake magnitude, the seismic analysis of bridge in liquefiable site has become an important engineering problem. In order to investigate the influence of pile-soil interaction and pile-soil liquefaction on seismic response of a railway three-span continuous beam-arch composite bridge in liquefiable site, ANSYS finite element calculation software is used in this paper. Based on m-value method and P-Y curve method, the full pile model 鈪，

本文编号：2418485