中央开槽箱梁涡激共振特性及抑振措施机理研究

桥梁结构涡激振动实例及减振措施比较研究摘要：针对设计中不被重视的涡激共振问题，讨论了桥梁结构涡激振动及其响应分析的复杂性，介绍了几座国外大跨度桥梁结构的涡激振动问题，并比较分析了这些桥梁结构所采用的不同减振措施方案，推荐设计阶段首先选择气动控制措施来抑制桥梁涡激振动，而已建成的桥梁发生涡振病害则更适宜选用机械减振措施。

abstract： in view of the ignored problem of vortex-induced resonance in design， this article analyzes vortex-induced vibration of bridge structure and the complexity of response analysis. the vortex-induced vibration problem of some foreign large span bridge structures is introduced and different vibration reducing measures of these bridges are analyzed and compared. it is recommended that pneumatic control measures be firstly used to control thevortex-induced vibration of bridges in design phase， while for vortex-induced vibration of built-up bridges， mechanical vibration reduction measures are more appropriate.关键词：桥梁；涡激振动；振动控制；气动措施key words： bridge；vortex-induced vibration；vibration control；pneumatic measures中图分类号：u441 文献标识码：a 文章编号：1006-4311（2013）24-0100-030 引言桥梁结构涡激振动是由气流流经钝体的桥梁断面后产生分离而形成交替脱落的旋涡所引起的横风向振动，当风流的旋涡脱落频率接近结构的自振频率时就会诱发结构的涡激共振，大幅度的涡激共振会造成桥梁构件的疲劳破坏并严重影响行车安全。

中央开槽箱梁涡激共振特性及抑振措施机理研究杨婷;周志勇【摘要】To study vortex-induced resonance characteristics and anti-vibration measures'mechanism of central-slotted box girders,the large-scale sectional model vibration measurement,pressure measurement and CFD were employed.A long-span cable-stayed bridge over Yangtze River was taken as an example to conduct wind tunnel tests of large-scale sectional model.The test results indicated that it is the maintenance rails located inside aerodynamic susceptible sites that cause the vortex-induced vibration of the bridge.CFD numerical simulation results showed that the upwind flow passing through the curved soffit plate is hindered by the inside maintenance rails to cause an increased width of dead water region in the wake of upwind box section,a continuous and intensive vortex shedding phenomenon occurs due to velocity gradient and the VIV of the bridge main beam section takes place;accordingly,the inside maintenance rails are proposed to offset the center line of the main beam with a certain distance,they are not an obstacle to the high-speed upwind flow;thus the flow separates at the location far away from the knuckle line and the size of dead water region in the upwind box wake is reduced to prevent the vortex shedding.The static pressure test results showed that when shifting the inside maintenance rails,the negative mean pressure at the soffit plate knuckle line,does not change dramatically,the fluctuating pressures on the upwind and downwind inclined panels can be reduced,and the fluctuatingenergy is dispersed without a consistent predominant frequency.Wind tunnel tests for the modified section were conducted and the results showed that the VIV of the bridge can be suppressed completely.%基于大比例节段模型风洞测振、测压试验及计算流体力学（Computational Fluid Dynamic，CFD）方法进行中央开槽箱梁涡激共振特性及抑振措施机理研究。