在大跨度拱桥的地震分析中,行波效应的影响备受关注,且在视波速的选择上有较大的区间,致使所得结论不统一。以湖南益阳茅草街大桥为研究对象,基于ANSYS软件建立了该大跨度中承式钢管混凝土(CFST)系杆拱桥的三维有限元模型,对茅草街大桥的地震反应进行了空间非线性时程分析,得到边拱、主拱拱脚弯矩,以及各拱顶位移等响应量随视波速变化曲线,据此分析了以上结构响应在行波作用下的变化规律。结果表明:行波效应对大跨度CFST拱桥地震响应有较大影响,行波效应的影响与结构特性以及地震波特性密切相关。
The influences of traveling wave have been paid great attention in seismic analyses for long-span arch bridge. However, the apparent wave velocities can be chosen in a wide range, so there have not yet been definite conclusions about the influence. Taking the Maoeaojie Bridge as an example a spatial finite element model for Concrete Filled Steel Tube (CFST) was established based on the software ANSYS, Then a three-dimensional nonlinear time history analysis for the bridge was inves- tigated. The moments of arch crown and springing, the longitudinal displacements of key positions and the relative displacements between the girders and ribs, due to different apparent wave velocities, were calculated. Results show that traveling wave has comparatively large influences on the seismic responses of long-span CFST arch bridges, and the influences are closely correlated with the characteristics of the bridge structure and the seismic wave.