无辅助墩的大边中跨比三塔PC斜拉桥结构刚度研究  

Study on Structural Stiffness of Three-pylon PC Cable-stayed Bridge with Large Sidespan-to-Midspan Ratio and Without Auxiliary Pier

作　　者：王少华 刘广宇 张黎明 徐德志 王显赫 WANG Shao-hua;LIU Guang-yu;ZHANG Li-ming;XU De-zhi;WANG Xian-he(Guangdong Road and Bridge Construction and Development Co.,Ltd.,Guangzhou,Guangdong 510660 China;Guangdong Communication Planning&Design Institute Group Co.,Ltd.,Guangzhou,Guangdong 510507 China;China Highway(Beijing)Engineering Materials Technology Co.,Ltd.,Beijing 100088,China)

机构地区：[1]广东省路桥建设发展有限公司,广东广州510660 [2]广东省交通规划设计研究院集团股份有限公司,广东广州510507 [3]中路交建(北京)工程材料技术有限公司,北京100088

出　　处：《公路交通科技》2024年第8期172-180,共9页Journal of Highway and Transportation Research and Development

摘　　要：为了解决无辅助墩、大边中跨比三塔PC斜拉桥结构刚度较小的问题,以西江特大桥为背景,分别选用设置辅助墩、优化结构体系、提高索塔高度、增大主梁和斜拉索刚度、加劲索体系等5种常用提高三塔斜拉桥结构刚度的方法,进行参数敏感性分析,同时结合防洪、通航、船撞和旧桥桥位等因素,综合选取有针对性的提高结构刚度措施。结果表明在边跨设置一个辅助墩对结构刚度和受力有明显的改善,但在边跨设置辅助墩受西江大堤、新旧桥墩位对齐和阻水比等的影响,不建议采用辅助墩方案提高桥梁刚度。在中塔两侧设置辅助索对边跨主梁挠度及应力改善不明显,在边塔两侧设置辅助索对主梁挠度和应力改善明显;采用中塔固结、边塔半漂浮约束体系能够有效抑制塔顶挠度,减少索塔根部弯矩效应值,提高结构刚度,中塔固结对主梁悬臂浇注施工也提高了有利条件;采用提高索塔高度仅能减少主梁挠度,对主梁应力影响有限,同时索塔提高将会带来成本的快速增长,增加施工难度,不建议采用提高索塔高度的方案。采用带翼缘板DP断面比常规DP断面受力更为合理,能够以较小代价,有效提高斜拉桥整体刚度。因此,推荐采用边塔两侧设置两对辅助索,带翼缘板DP断面主梁,中塔固结、边塔半漂浮约束体系的方案。To solve the low structural stiffness of three-pylon PC cable-stayed bridge with large sidespan-tomidspan ratio and without auxiliary pier,the Xijiang Grand Bridge was taken as the study background,5 commonly used methods(i.e.,setting auxiliary piers,optimizing structural systems,increasing cable pylons’height,increasing stiffness of main beams and stay cables,and stiffening cable systems)were selected to improve the structural stiffness of three-pylon cable-stayed bridge.Based on the parameter sensitivity analysis,the measures for improving structural stiffness were selected according to the factors of flood control,navigation,ship collision and old bridge position.The result indicates that setting an auxiliary pier at sidespan significantly improves the structural stiffness and stress;however,the installation of auxiliary piers on sidespan is affected by the factors of Xijiang embankment alignment,the alignment of new and old bridge piers,and the water resistance ratio.Therefore,it is not recommended to use auxiliary pier schemes to improve the bridge stiffness.The installation of auxiliary cables on both sides of central pylon does not significantly improve the deflection and stress of the sidespan main beam;however,setting auxiliary cables on both sides of side pylon significantly improves the deflection and stress of the main beam.Combining with middle pylon consolidation and side pylon semi-floating constraint system can effectively suppress the pylon top deflection,reduce the bending moment effect at the cable pylon root,and improve the structural stiffness.The consolidation of central pylon also improves the favorable conditions for the cantilever pouring construction of main beam.Increasing the height of cable pylon can only reduce the main beam deflection,and has limited influence on the main beam stress.Simultaneously,increasing the pylon height will bring a rapid increase in costs,and increase the construction difficulty.It is recommended not to adopt the scheme of increasing pylon height.The use of

关 键 词：桥梁工程 无辅助墩 大边中跨比 三塔PC斜拉桥 结构刚度 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]