斜风作用下大跨度斜拉桥双悬臂状态抖振性能  

BUFFETING PERFORMANCE OF DOUBLE-CANTILEVER STATE OF A LONG-SPAN CABLE-STAYED BRIDGE UNDER YAWED WIND

作　　者：朱乐东[1] 王淼[1] 郭震山[1] 丁泉顺[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室及桥梁工程系,上海200092

出　　处：《工程力学》2006年第4期86-92,共7页Engineering Mechanics

基　　金：国家自然科学基金面上项目(50378068)

摘　　要：通过气弹模型风洞试验对斜风作用下湛江海湾大桥施工阶段最长双悬臂状态的抖振性能进行了研究，结果显示：对于大跨度斜拉桥梁抖振响应法向风不一定是最不利的情况；抖振响应随风偏角呈非单调变化，最大值可能在0°～15°风偏角范围内发生；抖振响应随风速的增加近似地按两次曲线增加，并且基本固有模态对抖振响应的贡献占到了主要成份；最长双悬臂状态塔顶纵向抖振响应显著地大于裸塔塔顶纵向抖振响应，而两者随风偏角的变化形态也互不相同。试验和分析结果的比较表明，只要解决好诸如气动导纳等气动参数的取值问题，可以对大跨度桥梁抖振响应作出合理的理论预测。The buffeting performance of the longest double-cantilever state of Zhanjiang Bay Bridge under construction is investigated trough a wind tunnel test of aeroelastic model. The result shows that the normal wind case may not be the most unfavorable case for the buffeting responses of long-span cable-stayed bridges. The variation of the buffeting responses is not monotonous with the increase of wind yaw angle, and the maximal values may occur at a wind yaw angle between 0° and 15°. The buffeting responses grow with the increase of wind speed according to a quadratic curve approximately, and the contribution of the fundamental natural mode to the buffeting responses takes a dominant portion. It is also found that the longitudinal buffeting response at the tower top of the longest double-cantilever state is significantly larger than that of the free-standing tower state, and the variation patterns of the longitudinal response with the wind yaw angle are different for these two structural states. The comparison between experimental and computed results shows that a reasonable theoretical prediction of buffeting responses can be attained so long as the determination of aerodynamic parameters, such as aerodynamic admittance functions, is solved properly.

关 键 词：桥梁与隧道工程 大跨度斜拉桥 双悬臂状态 斜风 抖振响应 气弹模型风洞试验 抖振分析 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]