以南京江心洲大桥为工程背景,基于Ohtsuki博士提出的空间缆索线形计算方法,对空间缆索自锚式悬索桥的主缆线形计算方法进行研究,推导空间主缆线形的迭代算法;针对自锚式悬索桥的受力特点,在缆索初始、精细平衡状态分析的基础上,增加修正平衡状态分析来考虑由于主梁和主塔压缩引起的主缆线形及内力变化;根据几何相容及力的平衡条件,确定索夹的安装位置,并给出空缆状态下主鞍座、吊索横梁的预偏量以及主鞍座的预抬量等控制参数。计算结果表明:自锚式悬索桥体系转换过程中缆索的几何非线性效应显著,体现在空缆到成桥状态主缆有较大位移,主缆与主鞍座空间切点位置也会有较大的变化。
Taken Nanjing Jiangxinzhou Bridge as the engineering background, the main cable curve of selfanchored suspension bridge was researched based on the caleulation method for spatial eable eurve proposed by Ohstuski, and an iteration method of spatial cable curve was derived. According to the mechanical characteristics of self-anehored suspension bridge, iterative correction balance analysis was added based on initial and fine balanee analysis to consider the changes of main cable curve and internal forces caused by the eompression of the main pylon and the main girder. According to the geometric compatibility and the balanee of the forces, the locations of cable clamp were fixed, the structure control parameters such as pre-displacements of saddle and eross beam, and preelevation of the main saddle, ete. were obtained. The results show that serf-anchored suspension bridge has significant geometrie non- linear effeetiveness in strueture system transformation. The main cable has large displacement and the spatial tangent points of main cable with main saddle change a lot from free cable to finished bridge.