三塔四跨悬索桥施工阶段颤振性能研究  

Research on Flutter Stability of Three-Tower Four-Span Suspension Bridge at Construction Stage

作　　者：王盛铭 莫威 杨海忠 唐浩俊[2] 李永乐[2] WANG Shengming;MO Wei;YANG Haizhong;TANG Haojun;LI Yongle(Wenzhou Oujiang River Estuary Bridge Co.,Ltd.,Wenzhou 325002,China;Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]温州瓯江口大桥有限公司,浙江温州325002 [2]西南交通大学桥梁工程系,四川成都610031

出　　处：《世界桥梁》2024年第4期92-98,共7页World Bridges

基　　金：四川省自然科学基金项目(2022NSFSC0004,2022NSFSC0431)。

摘　　要：为了解双主跨悬索桥加劲梁吊装期间颤振稳定性,以跨度为(230+800+800+348)m三塔四跨悬索桥为背景,分析该桥加劲梁吊装期间的颤振性能。建立该桥不同吊装阶段三维有限元模型,分析竖弯、扭转模态特性,采用理想平板颤振临界风速理论公式计算桥梁不同吊装阶段及各模态组合下的颤振临界风速,以确定最不利吊装阶段及模态组合;基于此,设计节段模型风洞试验测试原断面及上桥面中央增设竖向稳定板断面桥梁颤振临界风速。结果表明:三塔四跨悬索桥施工阶段的模态特性复杂,颤振分析时模态组合需考虑两主跨间的振动关系;该桥吊装率为8.5%和19.8%时,颤振临界状态由以北侧主跨振动为主的扭弯模态组合确定,吊装率≥29.3%时,颤振临界状态由以南侧主跨振动为主的扭弯模态组合确定,最不利吊装率为40.8%;该桥加劲梁原断面的颤振性能较差,在上桥面中央增设竖向稳定板可以有效提升桥梁的颤振临界风速。This paper studies the flutter stability of the suspension bridge with two main spans during the erection of the stiffening girder.An existing suspension bridge with two main spans of 800 m and two side spans of 230 and 348 m is used as a case.The different erection stages of the suspension bridge were numerically simulated to analyze the characteristics of the vertical and torsional vibration modes of the bridge.The equation to calculate the ideal flutter critical wind velocities on flat deck was used to calculate the flutter critical wind velocities at different erection stages of the stiffening girder and under different combinations of vibration modes,to determine the most unfavorable erection stage and mode combination.Based on the calculations,wind tunnel tests were conducted to investigate the flutter critical wind velocities of the original stiffening girder and those of the stiffening girder equipped with vertical stabilizers along the longitudinal centerline of the bridge.It was shown that the modal characteristics of the three-tower four-span suspension bridge at the construction stage were complex,during the flutter analysis,the intervention of one main span to the other should be considered.When the erection of the stiffening girder was completed at rates of 8.5%and 19.8%,the flutter critical state should be determined in accordance with the flexural-torsional mode combination with vibrations of the north main span as the dominance.When the erection of the stiffening girder was completed at a rate of 29.3%or above,the flutter critical state should be determined in accordance with the flexural-torsional mode combination with vibrations of the south main span as the dominance,and the completion of 40.8%was the most unfavorable condition.The flutter critical wind velocities of the original stiffening girder of the bridge were low,after added with vertical stabilizers along the longitudinal centerline of the bridge,the flutter critical wind velocities have been effectively improved.

关 键 词：三塔四跨悬索桥 施工阶段 颤振性能 模态组合 吊装率 竖向稳定板 风洞试验 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U441.3[交通运输工程—道路与铁道工程]