平潭海峡元洪航道主桥施工阶段抖振性能试验研究

Experimental Study on Buffeting Performance of Main Bridge of Yuanhong Waterway in Pingtan Strait

摘要: 桁架梁因为其独特的断面特征，被广泛应用于大跨度桥梁之中。但由于桁架杆件众多，阻风效应明显，容易发生较大的抖振响应。本文以平潭海峡元洪航道主桥为工程背景，采用风洞试验方法对其施工阶段的抖振问题进行研究，结果表明：在最大单悬臂施工阶段，风向角对结构的抖振响应有明显的影响，尤其是扭转位移；由于结构特性的不同，最大单悬臂状态最大抖振位移发生在横桥向，而最大双悬臂状态的最大抖振位移发生在竖桥向；在设计基准风速下，最大单悬臂状态和最大双悬臂状态的最大抖振位移分别发生在0˚和15˚风向角下。

Abstract: Truss beams are widely used in long-span bridges because of their unique cross-section features. However, due to the large number of truss members, the wind blocking effect is obvious, and a large buffeting response is likely to occur. In this paper, the main bridge of Yuanhong Waterway in Pingtan Strait was taken as the researching object, and the wind tunnel test method was used to study the buffeting problem in the construction stage. The results showed that in the maximum single cantilever construction stage, the wind direction angle has a significant effect on the buffeting response of the structure, especially for the torsional displacement. Due to the different structural characteristics, the maximum buffeting displacement of the largest single cantilever state occurs in the transverse bridge direction, and the maximum buffeting displacement of the maximum double cantilever state occurs in the vertical bridge direction. At the design reference wind speed, the maximum buffeting displacement of the maximum single cantilever state and the maximum double cantilever state occurs at 0° and 15° wind direction angles, respectively.