多塔斜拉桥风致抖振响应的粘滞阻尼器控制研究  

CONTROL OF WIND-INDUCED BUFFETING RESPONSES OF A MULTI-TOWER CABLE-STAYED BRIDGE USING VISCOUS DAMPERS

作　　者：丁幼亮[1] 耿方方[1] 葛文浩[1] 宋建永[2] 李万恒[2] 王玉倩[2] 

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京210096 [2]交通运输部公路科学研究院,北京100088

出　　处：《工程力学》2015年第4期130-137,共8页Engineering Mechanics

基　　金：国家重点基础研究计划(973计划)项目(2015CB060000);国家科技支撑计划项目(2014BAG07B01);国家自然科学基金项目重点项目(51438002);江苏省"六大人才高峰"项目(1105000268)

摘　　要：以六塔斜拉桥型的嘉绍大桥为工程背景,基于ANSYS瞬态动力学分析功能进行了嘉绍大桥风致抖振响应的非线性时域分析,在此基础上研究了采用粘滞阻尼器的多塔斜拉桥结构减振控制效果。研究结果表明:1)多塔斜拉桥主梁和桥塔风振控制存在最大减振率,阻尼指数α愈小,最大减振率对应的阻尼系数c也愈小;2)嘉绍大桥主梁跨中处设置刚性铰使主梁横桥向抖振响应显著增大,设置粘滞阻尼器后主梁中跨横向位移的最大减振率达到近50%;3)嘉绍大桥采用次边塔与主梁固结的部分约束体系,使得次边塔的塔底内力明显大于其余塔的塔底内力,设置粘滞阻尼器后次边塔塔底内力的最大减振率达到近55%;4)设置粘滞阻尼器使得多塔斜拉桥各塔和各梁跨的风振响应幅值趋于一致。因此,对于抖振响应相对较小的塔和梁跨其减振效果相对较小。This paper presents an investigation for the mitigation of wind-induced buffeting responses of Jiashao Bridge, a six-tower cable-stayed bridge. A time-domain procedure for analyzing buffeting responses of the bridge is implemented in ANSYS using a transient dynamics-analysis function. The effectiveness of viscous fluid dampers on the mitigation of buffeting responses of the multi-tower cable-stayed bridge is further investigated. The analysis results reveal that: 1) For wind-induced vibration control of bridge deck and tower of the multi-tower cable-stayed bridge, the reduction ratio increases with the increase of damping coefficient c up to a certain level, giving maximum values for its reduction ratio. Moreover, the smaller the damping exponent α, the smaller damping coefficient c corresponding to the maximum reduction ratio; 2) The installation of a rigid hinge in the middle span of the bridge deck will significantly increase the lateral buffeting response of the bridge deck. The maximum reduction ratio for the lateral buffeting displacement in the middle span of the bridge deck is about 50% using viscous dampers; 3) In Jiashao Bridge, the secondary side towers restricted with the bridge deck result in a concentration effect of base shears and moments. Thus, the base forces of secondary side towers are significantly larger than those of other bridge towers. The maximum reduction ratio for the base forces of secondary side towers is about 55%, using viscous dampers; 4) The installations of viscous fluid dampers are beneficial for the uniform distributions in the wind-induced responses for each tower and each span of the multi-tower cable-stayed bridge. Therefore, the vibration reduction effect is relatively small for those towers and spans with relatively small wind-induced responses.

关 键 词：多塔斜拉桥 风致响应 粘滞阻尼器 振动控制 刚性铰 

分 类 号：U441.3[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程]