分体式钢箱梁竖向涡振检修轨道气动措施风洞试验研究  

Aerodynamic countermeasures of maintenance rail for vertical vortex-induced vibration of twin steel box girder based on wind tunnel test

作　　者：孙洪鑫[1] 黄文俊 温青[1] 陈魏 王修勇[1] SUN Hongxin;HUANG Wenjun;WEN Qing;CHEN Wei;WANG Xiuyong(School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学土木工程学院,湖南湘潭411201

出　　处：《铁道科学与工程学报》2023年第12期4636-4644,共9页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52078210);湖南省杰出青年科学基金资助项目(2021JJ10003)。

摘　　要：双分体式钢箱梁具有良好的颤振性能,但在常遇风速内易发生涡激振动。为研究双分体式钢箱梁的涡激振动性能及其抑振措施,以某跨径为658m的双分体式钢箱梁斜拉桥为背景,通过节段模型风洞试验,开展检修轨道与中央格栅等一系列独立气动措施以及多种联合气动措施对主梁涡振性能的优化研究。试验结果表明:1)在常遇风速下,原始断面在5个来流攻角(α=0°,±3°,±5°)中均观测到大幅竖向涡激振动,需采取抑振措施来抑制主梁涡激振动,结构阻尼提升至1.48%时涡振振幅仍未满足限值要求,完全消除主梁涡激振动需将阻尼比提升至2.3%;2)优化检修轨道位置能有限减小主梁竖向涡激振动,减少幅度在12.8%~29.6%之间;3)在分体式双箱梁中央开槽处添加中央格栅能大幅减小主梁竖向涡振振幅,相较原始断面减少了60%以上;4)检修轨道与中央格栅联合减振效果不如独立添加中央格栅气动措施,但这2种气动措施联合稳定板能有效控制主梁涡激振动,且相较原始断面,主梁涡振振幅下降了78%以上,在此基础上对中央开槽的封堵率以及检修轨道与外侧斜腹板之间的间距进行优化,最终得到一种双分体式钢箱梁断面涡激振动抑振措施,使主梁竖向涡振振幅减少了96.9%。研究成果可为双分体式钢箱梁涡激振动抑制气动措施方案提供参考。Twin steel box girder possesses good flutter performance,but it is prone to generate vortex-induced vibration(VIV)under the conditions of frequent wind speeds.In order to study the properties of VIV of twin steel box girder and its vibration suppression measures,section model wind tunnel test was conducted.This study focused on a 658-meter-span twin steel box girder cable-stayed bridge and investigated a series of independent aerodynamic countermeasures,including the maintenance rail and central grille,as well as combined aerodynamic strategies,to optimize the main beam’s VIV performance.The results show that:(1)at the frequent wind speeds,large vertical VIV is observed in the original section at five wind attack angles(0°,±3°,±5°),and vibration suppression measures need to be taken to suppress the VIV of the main beam.When the structural damping is increased to 1.48%,the VIV amplitude still cannot meet the limit requirements.Completely eliminating the VIV of the main beam requires increasing the damping ratio to 2.3%;(2)strategic optimization of the maintenance rail location effectively reduces the main beam’s vertical VIV by 12.8%to 29.6%;(3)adding a central grille at the centrally-slotted of twin steel box girder can significantly reduce the vertical VIV amplitude of the main girder by more than 60%compared to the original section;(4)the combined vibration reduction effect of the maintenance track and the central grille is not as good as the independent addition of the central grille aerodynamic measures.However,the combination of these two aerodynamic measures and the stabilizing plate can effectively control the VIV of the main beam.Compared to the original section,the VIV amplitude of the main beam can be decreased by more than 78%.Based on this,the blocking ratio of the centrally-slotted and the spacing between the maintenance rail and the outer inclined web are optimized,and a twin steel box girder section VIV suppression measure is finally obtained,which reduces the vertical VIV amplitude of the

关 键 词：斜拉桥 双分体式钢箱梁 涡激振动 风洞试验 检修轨道 中央格栅 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]