基于虚位移原理的自锚式悬索桥实用计算方法

The practical calculation method of self-anchored suspension bridge based on the virtual displacements principle

基于挠度理论和虚位移原理,分析自锚式悬索桥各组成部分的受力状态,分别导出在各种荷载作用下以三角级数法表示的加劲梁挠度内力和变形公式,并结合Newton-Simpson迭代法来确定活载索力,提出了计算自锚式悬索桥加劲梁内力及变形的实用计算方法,并编制相应的计算分析程序。以长沙湘江三汊矶大桥(主跨328 m的双塔五跨自锚式悬索桥)为例,通过与有限位移理论的计算结果相比较,证明该方法简单、方便,计算结果准确可靠;如果所设计的结构吊索分布比较均匀,挠度理论与有限元的计算结果比较一致;这说明可以采用本方法来研究自锚式悬索桥的设计参数对结构内力与变形的影响,尤其是在方案设计阶段,可以用于很方便地选定结构主要设计参数。

Based on the deflection theory and the virtual displacement principle, the stress state of different components of the self- anchored suspension bridge was analyzed; the formulas denoted by trigonometric series for computing the internal force and deformation of the stiffened girder, were derived under a variety of loads respectively, and the cable force was determined under the live load combined with Newton - Simpson iteration approach. A practical method to calculate the internal force and deformation of the stiffening girder of self - anchored suspension bridge was presented by the corresponding analysis program. Then, Sanchaji Bridge across Xiangjiang River in Changsha （ self - anchored suspension bridge, main span of 328 m）, was taken for example, the calculation results compared with finite displacement theory, proved it is a simple, convenient, accurate and reliable method ; if the distribution of the hangers is uniform, the results were consistent between deflection theory and finite displacement theory. This shows that, this method proposed by this paper can be used to study the influences of design parameters self - anchored suspension bridge, on the internal force and deformation of especially in the preliminary design stage. Moreover, this mothed can be used to select the main design parameters easily.