混合梁斜拉桥锚跨异型混凝土箱梁空间受力仿真分析

The spatial stress simulation analysis for special-shaped concrete box girder in the anchor span of hybrid girder cable-stayed bridge

大跨度混合梁斜拉桥锚跨主梁具有受力形式复杂的特点,在实际应用中很难把握其实际受力情况。以万州长江公路三桥锚跨异型混凝土箱梁为工程背景,通过有限元仿真计算分析手段,分别对锚跨混凝土箱梁在主梁截面弯矩最大、弯矩最小、轴力最大、轴力最小工况下的空间应力分布、索梁锚固区受力情况以及索梁锚固区横截面剪力滞效应进行分析。研究结果表明:各工况下,锚跨混凝土箱梁基本上处于受压状态,少数索梁锚固区对应的底板位置和顶板位置存在拉应力作用,最大拉应力与最大压应力均满足规范要求。

The anchor span of long-span hybrid girder cable-stayed bridge has the characteristic of complexity of stress and it is difficult to grasp its actual force condition in the practical application. The special-shaped concrete box girder in the anchor span of the Third Wanzhou Yangtze River Highway Bridge regarded as the engineering background,finite element simulation is used to analyze the spatial distribution of stress,force condition and shear lag effect in the cross section of cable-girder anchorage zone in the conditions of maximum moment,minimum moment,maximum axial force and minimum axial force in the cross section of main girder. The results show that the concrete box girder in the anchor span is in pressured state basically,few positions in bottom plate and top plate of the cablegirder anchorage zone are under tensile stress,and the maximum tensile stress and compressive stress all meet standard requirements in various operation conditions.