悬索桥空间主缆分析

Analysis of spatial cable of suspension bridge

为了确定悬索桥空间主缆恒载线形,根据已有的二维模型,提出了一个三维主缆线形计算方法.直接从三维索的几何方程和平衡方程出发推导了索形迭代计算方法,该方法将三维主缆投影到2个平面上分别考虑几何边界条件和力的平衡条件,考虑了倾斜吊杆的影响,引入梯度迭代法,推导了三维主缆的迭代方程,给出了具体计算分析的迭代流程;采用C++语言编制了主缆三维恒载线形分析程序CF3D.基于该方法和程序对一座悬索桥的主缆进行了恒载线形的迭代计算分析.研究结果表明:该方法精度完全能满足工程计算要求,迭代计算出的主缆线形平顺。该方法具有使用方便、精度高等优点,适用于多跨空间缆索悬索桥.

For determining the cable shape of suspension bridge with spatial cables at dead load.A three dimensional analysis model is presented in this paper based on the existing two dimensional method.Directly from geometry and equilibrium equation of three dimensional cable a iterative method to compute cable shape has been deduced.In the method,the geometry of main cable is projected onto two planes to consider the geometry boundary conditions and force equilibrium respectively and the effect of inclined hanger is also considered.The gradient method is used to deduce the iterative equation of three dimensional main cables.A program CF3D to analyze the shape of three dimensional main cables at dead load is compiled using C＋＋ language.Based on the presented method and program a suspension bridge＇s main cable shape at dead load was computed by iterative method.The results show that the accuracy of this method can meet the requirements of engineering calculations completely;the iteratively calculated cable shape is smooth.The method is accurate and convenient and applicable to multi-span suspension bridge with spatial cables.