超大跨度斜拉桥几何非线性精细化分析

Refined Geometrical Nonlinear Analysis for Super-long-span Cable-stayed Bridge

基于几何非线性分析的CR列式全量法,采用悬链线索单元模拟斜拉索,分析主跨为1 088 m的苏通大桥施工过程几何非线性影响。研究结果表明:该方法具有很高的精度和效率;经典的几何非线性分析方法引起的恒载应力相对误差在10%以内,主梁成桥标高相差超过0.5 m;对于张拉工况,经典方法增加荷载步数并不能提高其计算精度。建议超大跨度斜拉桥施工控制时采用精细化的分析方法。

Based on CR formulation superposition method for geometrical nonlinear analysis, the catenary cable element was used to simulate stay cable. Nonlinear influence for Sutong Bridge whose main span reaches 1 088 m during construction was studied. It is proved that accuracy and efficiency of the method are very high. Although the relative error of dead load stress caused by classic geometrical nonlinear analysis method is no more than 10 %, it influences configuration of bridge significantly. The maximal error of elevation of main girder is more than 0. 5 m when classic method is used. Using the classic method, increase of load steps can＇t make increase of calculation accuracy under the condition of tensile. So authors recommended to use refined analysis method in construction control.