大跨度钢箱梁斜拉桥施工阶段几何非线性分析

On Geometrically Nonlinear Analysis of Long- Span Steel- Box Girder Cable- Stayed Bridge

作为一种高次超静定柔性受力体系，与连续梁和桁架梁相比较，斜拉桥特别是大跨度斜拉桥，几何非线性影响较为突出，而且影响因素也较多。目前认为，影响斜拉桥几何非线性的因素主要包括三个方面垂度效应、大变形效应、弯矩一轴力组合效应。本文以某主跨跨径680m的双塔双索面钢箱梁斜拉桥为例，采用Midas Civil建立有限元模型，对斜拉桥进行了成桥计算并分析了施工阶段恒载作用下的几何非线性。

As a kind of flexible structure with high static in - determination, compared with continuous beam andtruss beam bridges, the effect of geometrical non - linearity of cable - stayed bridge is more outstanding and the in-fluence factors are also more, especially for long - span cable - stayed bridge. The effect of geometrical non - linear-ity of cable - stayed bridge includes three aspects ： cable - sage effects, combined effects of bending moment and axi-al force and large displacement. This paper takes the twin towers and double - cable - plane steel box girder withmain span of 680m as an example. The bridge calculation has been carried out by Civil Midas and geometric non -linearity of the bridge under dead load is analyzed.