摘要
大跨径悬索桥在运营状态下,加劲梁的往复运动极易引发梁端伸缩装置、支座、阻尼器的耐久性问题。针对大跨径公路悬索桥在复杂随机荷载作用下加劲梁纵向运动特征及控制措施不明确的问题,以某在建超大跨径悬索桥为工程背景,研究了随机车流和风荷载作用下加劲梁梁端的纵向运动特性以及采用黏滞阻尼器和电涡流—摩擦组合型阻尼器为纵向阻尼系统共同控制下的减振效果,并考虑了阻尼器性能退化的影响。研究结果表明,在运营阶段大桥梁端纵向运动由车致拟静态运动和风致低阶纵飘模态振动共同产生;在风速较低时,梁端纵向运动以车流荷载引起的拟静态运动为主,随着风速的增大,风致低阶纵飘模态振动逐渐占据主导地位,并与拟静态运动共存;纵向阻尼系统对梁端纵向运动的控制效果良好,但随着电涡流—摩擦组合型阻尼器最大摩擦力的减小,以及黏滞阻尼器漏油百分比的增大,控制效果逐渐下降;当黏滞阻尼器的漏油百分比达到20%后,其控制效果以及两种阻尼器的耗能功率比均趋于稳定,此时控制效果仍然较好,说明混合型梁端纵向阻尼系统具有优越的鲁棒性。
In the operational state of long-span suspension bridges,the reciprocating motion of the stiffening girder can easily lead to durability issues with the expansion joints,bearings,and dampers.Addressing the unclear longitudinal motion characteristics and control measures of the stiffening girder under complex random loading conditions for long-span highway suspension bridges,this paper takes a certain under-construction ultra-long-span suspension bridge as the engineering background.It investigates the longitudinal motion characteristics of the stiffening girder ends under the action of random traffic flow and wind loads.The study also explores the vibration reduction effects under the control of a longitudinal hybrid damping system using fluid viscous dampers and eddy current-friction compound dampers,taking into account the effects of performance degradation in both dampers.The research results indicate that during the operational state,the longitudinal motion of the girder ends is jointly caused by quasi-static motion induced by traffic and low-order longitudinal drift mode vibration induced by wind.At lower wind speeds,the longitudinal motion of the girder ends is primarily induced by quasi-static motion from traffic loads.As the wind speed increases,the wind-induced low-order longitudinal drift mode vibration gradually becomes dominant,coexisting with quasi-static motion.The longitudinal hybrid damping system effectively controls the longitudinal motion of the girder ends.However,as the maximum friction force(f)of the eddy current-friction compound damper decreases and the oil leakage percentage of the fluid viscous damper increases,the control effectiveness gradually diminishes.When the oil leakage percentage(μ)of the fluid viscous damper reaches 20%,the control effectiveness and the power dissipation ratio of the two dampers stabilize.At this point,the control effectiveness remains at a relatively high level,indicating that the longitudinal hybrid damping system has superior robustness.
作者
王仁贵
陈智
封周权
魏乐永
张弘毅
陈政清
WANG Ren-gui;CHEN Zhi;FENG Zhou-quan;WEI Le-yong;ZHANG Hong-yi;CHEN Zheng-qing(CCCC Highway Consultants Co.Ltd.,Beijing 100010,China;Hunan University,Changsha 410082,China)
出处
《公路》
北大核心
2024年第12期131-141,共11页
Highway
基金
国家重点研发计划项目,项目编号2021YFB1600301。
关键词
大跨径悬索桥
加劲梁纵向运动
黏滞阻尼器
电涡流—摩擦组合型阻尼器
阻尼器性能退化
控制水平
long-span suspension bridge
longitudinal motion of stiffening girder
fluid viscous damper
eddy current-friction compound damper
damping performance degradation
control effectiveness
