特大跨度斜拉桥变形的几何非线性效应分析

为了充分考虑几何非线性的影响，以某主跨1088m的特大跨度斜拉桥为工程背景，考虑初始安装线形的影响，按线性、不考虑斜拉索垂度的部分几何非线性和完全几何非线性3种模式计算了结构施工全过程的响应，分析了悬臂施工过程中及全桥合龙后主梁变形的几何非线性效应．结果表明，随斜拉索长度和主梁悬臂长度的增大，结构的几何非线性效应显著增大，斜拉索垂度效应对斜拉桥几何非线性效应的贡献达70％以上.

Effect of Geometric Nonlinearity on Deformation of Extra-Long-Span Cable-Stayed Bridge

To fully take the effect of geometric nonlinearity on the deformation of extra-long-span cable-stayed bridges into account, the effect of geometric nonlinearity on the deformation of a cable-stayed bridge with a main span of 1 088 m, as an example, was analyzed on the basis of the girder initial fabrication profile and three calculation modes, i. e. , linearity, partially geometric nonlinearity without considering the sag of stay-cables and fully geometric nonlinearity, and the effects during the cantilever construction and after bridge closing were investigated. The research results show that the geometric nonlinear effect enhances distinctly and the sag effect of stay-cables stands out factors. with the increases of cable length and cantilever length more prominently in the three geometric nonlinearity