梁柱效应对大跨度斜拉桥地震响应的影响研究

斜拉桥是高柔度超静定结构，具有强烈的几何非线性行为。以一大跨度斜拉桥为例，使用MIDAS/civil2012有限元软件建立三维有限元动力计算模型，并对其动力特性进行分析。在此基础上，建立模型A（不考虑梁柱效应）和模型B（考虑梁柱效应），其均考虑斜拉索的垂度效应和结构的大变形效应。参考JTG/TB02-01-2008《公路桥梁抗震设计细则》提供的反应谱数据，采用CQC振型组合方法对上述2组模型进行地震仿真分析并对其位移和内力进行比较。结果表明：梁柱效应对大跨度斜拉桥的动力特性有较大影响；由于梁柱效应，在地震作用下结构的位移和内力都有所增大，且纵桥向＋竖向的地震作用比横桥向＋竖向地震作用结构的梁柱效应明显。研究结论可为以后大跨度斜拉桥动力分析提供理论依据。

Research on Influences of Beam-column Effect on Seismic Response of Large-span Cable-stayed Bridges

The cable-stayed bridges are high-flexibility and hyperstatic structures and have strong geometrical non-linear behavior. With a large-span cable-stayed bridge as an example, this paper establishes a definite element dynamic calculation model with MIDAS/civil 2012 definite element software and analyzes its dynamic properties. On this basis the paper constructs model A （ not considering the beam-column effect） and model B （ considering the beam-column effect） , both of which consider the sag effect of stayed cables and the large deformation effect of structures. By reference to the response spectrum data provided in JTG/T B02-01-2008 “Rules for Seismic Design of Highway Bridges”, the paper conducts seismic simulation analysis for the above two models by means of CQC vibration type combination method and compares their displacements and internal stresses. The results show that the beam-column effect has big influences on dynamic properties of large-span cable-stayed bridges; both displacement and internal force of structures increase due to the beam-column effect, and the beam-column effect on earthquake affected structures in longitudinal direction＋vertical direction is more obvious than that in transverse direction＋vertical direction. The research conclusion can provide theoretical basis for dynamic analysis of large-span cable-stayed bridges in the future.