独塔部分地锚斜拉桥涡振气动抑振措施与气动影响研究  

Mitigation countermeasure on VIV and its effects on aerodynamics of partial gravity anchored cable-stayed bridge with a single tower

作　　者：祝志文 刘桂荣 沈焯悦 刘帅永 汤琴 ZHU Zhiwen;LIU Guirong;SHEN Zhuoyue;LIU Shuaiyong;TANG Qin(Department of Civil Engineering and Smart Cities,Shantou University,Shantou 515063,China)

机构地区：[1]汕头大学土木与智慧建设工程系,广东汕头515063

出　　处：《铁道科学与工程学报》2025年第2期757-769,共13页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52278509)。

摘　　要：为解决Π形截面双边箱主梁易引发涡振的问题,以结构复杂的独塔部分地锚斜拉桥为例,采用Ansys有限元软件建立全桥模型,根据动力特性分析的结果设计节段模型,开展不同风攻角和风速下的节段模型涡振试验,研究气动抑振措施及其气动影响。研究结果表明:在规范阻尼比水平、常遇风速范围和±3°风攻角范围内,原设计主梁断面在竖弯和扭转方向均发生了明显的涡激振动,竖弯涡振幅值明显超过规范限值。增设下稳定板或倒L形裙板能显著降低±3°风攻角范围内的竖弯涡振幅值,也能一定程度降低扭转涡振幅值,使得桥梁涡振满足规范要求。但5°风攻角时仅增设一种气动措施无法抑制涡振,需同时增设下稳定板和倒L形裙板。原主梁和增设气动措施的主梁在±3°风攻角范围内有足够的颤振稳定性,表明增设的涡振气动措施不影响原主梁的颤振稳定性。测力试验表明,与增设下稳定板基本不改变原主梁的阻力系数不同,增设倒L形裙板能明显减小原主梁阻力系数,且负风攻角下阻力降幅明显大于正攻角,表明倒L形裙板能流线化Π形截面主梁气动外形。增设倒L形裙板将明显增大升力和扭矩系数曲线斜率,预示竖弯和扭转气动阻尼的增大,因而能降低竖弯和扭转涡振,改善桥梁的抗涡振性能。研究结果能为大桥抗涡振设计提供依据,也能为同类桥梁抗风设计提供参考。In order to solve the problem of vortex-induced vibration(VIV)frequently observed in two-edged box girders withΠ-shaped cross-section in cable-stayed bridge,a case study on a single-tower partially ground-anchored cable-stayed bridge of complex structure was carried out.The full bridge model was established using Ansys software,and then the sectional model was designed based on the results of dynamic characteristics analysis.Sectional model VIV tests were carried out under different wind angles of attack and wind speed,followed by studies on mitigation countermeasures on VIV and their effects on bridge girder aerodynamics.The study shows that at the code-specified damping ratio,and in the range of prevailing wind speed and among wind attack angle of±3°,the original designed girder indicated significant VIV in both vertical and torsional directions,and the vertical VIV amplitude obviously exceeded the code limit.The addition of lower baffle plates or inverted L-shaped edge plates significantly reduced the vertical bending VIV amplitude within the wind attack angle range of±3°and also slightly reduced the torsional VIV amplitude,satisfying the code requirements for bridge VIV.However,if only one aerodynamic countermeasure was applied at the wind angle of attack of 5°,the vertical and torsional VIV still exceeded the code requirement.Therefore,the application of both the lower baffle plates and the inverted L-shaped edge plate is necessary to effectively suppress VIV of the bridge.The original designed girder and the aerodynamic modified girders have sufficient flutter stability in the wind angle of attack of±3°,showing that the aerodynamic countermeasures do not affect the flutter stability of the original girder.In addition,the installation of lower baffle plates basically does not change the drag coefficient of the original girder,while the installation of the inverted L-shaped edge plates significantly reduces the drag coefficient of the original girder.The installation of inverted L-shaped edge plate ob

关 键 词：涡振 部分地锚斜拉桥 双边箱主梁 抑振措施 力系数 气动机理 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]