结构连接对三塔悬索桥性能的影响线分析

摘要

In order to study the effect of structural connections on static performance, influence lines of three⁃pylon suspension bridges were analyzed. The Taizhou Yangtze highway bridge was a prototype, and its influence lines of structural response were calculated by limited displacement method, considering different cable⁃girder connections and pylon⁃girder connections. The effect of structural connections on the influence lines was also researched. The results show that, when center buckles were not assembled in three⁃pylon suspension bridges, the change of pylon⁃girder connections had an unobvious effect on the influence lines, including middle⁃span deflection of the girder, horizontal displacement at the top of pylons, and different value of main cable sided on the middle saddle. Also, when center buckles were assembled, the influence lines were changed remarkably, especially to amplitude in the part of local span, and to the shape in the part of adjacent span. Based on the variation of influence lines, the recommended structural connection for three⁃pylon suspension bridges was the rigid center buckle coupled with elastic stringer.%为研究不同结构连接形式对三塔悬索桥静力性能的影响，进行了三塔悬索桥静力影响线分析。以泰州长江公路大桥为原型，考虑了不同的塔梁连接和缆梁连接形式，采用线性化有限位移法对反映结构性能的三塔悬索桥关键参数影响线进行了计算，分析了不同缆梁连接和塔梁连接对三塔悬索桥结构影响线的变化情况。结果表明：无中央扣时，塔梁连接形式对主梁跨中挠度、桥塔塔顶水平位移、中间塔主缆力差等的影响线无显著影响；设置中央扣时，影响线跨内部分的幅值、邻跨部分的形状具有显著变化，应引起重视。综合不同缆梁连接、塔梁连接下的影响线变化情况，采用柔性中央扣＋弹性索的结构连接形式，对三塔悬索桥主梁竖向变形、中间塔受力状态及中间塔鞍座抗滑移均有利。