大跨径斜拉桥施工双悬臂状态抖振响应分析及控制  

Analysis and Control of Buffeting Response of Long-span Cable-stayed Bridges during the Construction Stage with Double Cantilever

作　　者：郭建民[1] 余晓琳[2] 

机构地区：[1]广州市市政工程设计研究院,广州510060 [2]华南理工大学交通学院,广州510640

出　　处：《防灾减灾工程学报》2005年第1期30-34,68,共6页Journal of Disaster Prevention and Mitigation Engineering

摘　　要：斜拉桥在施工状态时柔性大、振动频率较低,在紊流风的作用下梁端会产生较大的竖向抖振位移,而塔的摇头运动会在塔根引起较大的纵向弯矩。以某三塔斜拉桥为例,根据大跨度桥梁抖振响应有限元理论,分析和比较了5种不同的风缆设置方案以及设置临时支撑桩方案的抑振效果,并提出了一种有效的抑振措施。During construction cable-stayed bridges become more flexible with lower vibration frequency. The vertical buffeting response thus produced will be larger at the end of the beam because of turbulent winds. Moreover, larger longitudinal moment will be caused at the tail of tower by the shaking of the top of tower. In this paper, a three-tower cable-stayed bridge is considered. Based on the finite element buffeting theory of long-span bridges, the effect of five kinds of different measures of wind-cable and temporary support stake are analyzed and compared. Some useful results are obtained as follows: 1.When the cantilevered deck length is the largest, larger longitudinal moment at the tail of tower is mainly caused by first step of longitudinal moment. This value will potentially exceed its ultimate carrying capacity. It is necessary to apply some restraining measures to ensure wind-resisting safety of the long-span bridge at construction stage. 2.There are some buffeting-restraining effects by applying wind-cables to structure. Among the schemes discussed in this paper, setting wind-cables according to the scheme of beam end- boat will be more convenient during construction. Moreover, it is relatively cost-effective and thus recommended for application. 3.Setting temporary support stake can markedly reduce the buffeting response of the structure. In order to ensure safety at the construction stage, the construction must avoid typhonic days as possible as it can do, otherwise setting wind-cables or temporary support stake should be taken as buffeting-restraining measures.

关 键 词：斜拉桥 施工状态 抖振响应 风缆 抑振措施 

分 类 号：U443[建筑科学—桥梁与隧道工程]