板桁结合钢桁梁斜拉桥主梁体系受力分析研究

Force analysis on the main girder of the cable- stayed bridge with plate truss and steel truss beam

结合主跨800m的国内最大跨钢桁架斜拉桥设计,采用板梁组合法和等效格子梁法两种空间计算方法,对该类型斜拉桥的板桁结合钢桁梁进行受力分析对比。结果表明:板梁组合法或等效格子梁法均可以正确模拟整体桥面系参与主桁整体受力的特性,但板梁结合法能反映出桥面板沿桥纵向的剪力滞效应、上弦杆的受力更为真实、板桁结合部位的计算结果也更为直观,可优先选用该方法。

Based on the design of the largest span steel truss cable- stayed bridge whose main span is 800 m,the plate beam combination method and equivalent lattice beam method are used to analyze the stress of the combination of plate truss and steel truss girder for the cable- stayed bridges. The results show that the plate beam combination method and equivalent lattice beam method both can correctly simulate characteristics of the whole deck system participating in stress of the main truss overall,but the former one can reflect the shear lag effect of the bridge panels along the bridge longitudinal direction,and with this method the top chord stress is more real,and the calculation result of plate truss composite part is more intuitive,so this method can be preferred.