跨长江特大桥拉索涡激振动与风特性观测  

Observation of vortex-induced vibration and wind characteristics of cables across the Yangtze river bridge

作　　者：刘宗杰 祝志文[1,2] 陈魏 陈政清[1] LIU Zongjie;ZHU Zhiwen;CHEN Wei;CHEN Zhengqing(College of Civil Engineering,Hunan University,Changsha 410082,China;Department of Civil and Environment Engineering,Shantou University,Shantou 515063,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]汕头大学土木与环境工程系,广东汕头515063

出　　处：《铁道科学与工程学报》2020年第7期1760-1768,共9页Journal of Railway Science and Engineering

基　　金：国家重点基础研究发展计划(“973”计划)资助项目(2015CB057701);国家自然科学基金资助项目(51878269);湖南省研究生创新资助项目(521293361)。

摘　　要：为研究跨长江特大桥拉索风致振动的类别与风特性的关系,基于大桥健康检测系统和自开发的拉索振动监测系统,对荆岳长江大桥桥址风场特性进行监测,记录拉索振动数据并对拉索风致振动加速度与风场的相关性进行研究。研究结果表明:桥址平均风速的非平稳特性显著;随着风速增大湍流度逐渐减小。在低风速下,来流湍流强度较大,拉索振动随风速增大而增大;当风速增大时湍流强度逐渐减小,拉索振动加速度将减小;拉索振动可为平面内振动也可为平面外振动,为多模态风致涡激振动,且JB02号拉索在一定风速条件下面内振动与面外振动基本相同,当风速变化,可出现更高阶的振动。拉索面内涡激振动分段时程分析表明,拉索振动幅值增加,主导模态频率不改变,各模态振动幅值增加,但随风速的增大,拉索的涡激振动可在更高风速下被锁定,从而导致拉索发生更高阶的涡激振动。另外,湍流度小于40%时拉索振幅较大,湍流度增大拉索涡激振动加速度反而减小,且拉索的涡激振动只在特定的风向角下发生。In order to study the relationship between the wind-induced vibration type of the cable across the Yangtze River Bridge and the wind characteristics,based on the bridge health detection system and the self-developed cable vibration monitoring system,the wind field characteristics of the Jingyue Yangtze River Bridge site were monitored and recorded.The cable vibration data was studied and the correlation between wind-induced vibration acceleration and wind field was studied.The research shows that the average wind speed of the bridge site is not stable.With the increase of wind speed,the turbulence gradually decreases.At low wind speed,the incoming turbulence intensity is large,and the cable vibration increases with the wind speed increase.When the wind speed increases,the turbulent flow intensity decreases gradually,and the cable vibration acceleration will decrease.The vibration of the cable can be in-plane vibration or out-of-plane vibration.It is multimodal wind-induced vortex-induced vibration,and the in place-vibration of JB02 cable under the certain wind speed condition is basically the same as the out-of-plane vibration.When the wind speed changes,it can appear higher order vibration.The time-history analysis of the vortex-induced vibration in the cable plane shows that the vibration amplitude of the cable increases,the dominant mode frequency does not change,and the amplitude of each mode vibration increases.However,as the wind speed increases,the vortex of the cable increases.Vibration can be locked at higher wind speeds,resulting in higher order vortex-induced vibrations of the cable.In addition,when the turbulence is less than 40%,the amplitude of the cable is large,and the turbulence increases,and the vortex acceleration of the cable decreases,and the vortex-induced vibration of the cable occurs only at a specific wind direction angle.

关 键 词：拉索 涡激振动 风特性 多模态 现场监测 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]