П形截面主梁斜拉桥剪力滞效应分析

Shear Lag Effects of Cable-stayed Bridge with П-shape Cross-section Main Girder

以温州某П形截面预应力混凝土梁斜拉桥为背景,采用数值计算方法,通过分析自重、斜拉索索力、预应力、对称活载及其组合作用下的剪力滞效应问题,研究该种桥型主梁剪力滞系数的分布规律。结果表明,П形断面在单项荷载作用下的剪切变形从梁肋向两侧逐渐减小,且轴向力作用能减弱剪力滞效应;在作用效应组合下,截面出现负剪力滞现象,这亦为同类桥型设计应注意的问题。

With a pre-stressed concrete girder cable-stayed bridge with ∏-shaped cross-section in Wenzhou as an example, this paper studied the distribution rule of shear lag coefficient of this type of main girders by using numerical calculation method to analyze the shear lag effects with main Girders under dead load, cable power, pre-stressed force, symmetrical live loads and their combination. The results show that the shear deformation of the H：shaped cross-section under a single load decreases gradually from rib of girder to the two sides, and the axial force can weaken the role of shear lag effects, but there may be the phenomenon with negative shear lag effects under the combined effects, which is beneficial to the design of the same type of bridges.