山区峡谷地带大跨度桥梁风场特性试验  

Model test study of wind field characteristics of long-span bridge site in mountainous valley terrain

作　　者：陈政清[1] 李春光[1] 张志田[1] 廖建宏[2] 

机构地区：[1]湖南大学土木学院风工程试验研究中心,长沙410082 [2]湖南省交通规划勘察设计院,长沙410082

出　　处：《实验流体力学》2008年第3期54-59,67,共7页Journal of Experiments in Fluid Mechanics

基　　金：教育部高校博士点基金(项目编号20040532019.)

摘　　要：以主跨1176m的超大跨度悬索桥湘西矮寨大桥为工程背景,进行了桥址处峡谷地形模型的风场特性风洞试验研究。主要研究了山区峡谷风对桥梁结构抗风设计的影响。提出了由地形模型谷口前试验风场梯度风速与模型中桥位桥面高度处风速的实测对应关系,结合实际谷口前的梯度风速计算桥梁设计风速的方法。试验结果表明:峡谷内沿桥跨方向平均风剖面的分布具有明显不均匀性,不能用统一的剖面形式描述;桥面高度处风迎角明显高于规范要求的±3°之内的检验标准;峡谷风速放大效应需综合考虑测点高度和两侧山体地形的影响。Taking Aizhai bridge--a super long suspension bridge with a main span of 1176m as backgrond, this paper bring forward a way to test the wind field characteristic of deep valley in wind tunnel. The effects of valley wind on design wind speed of bridge were mainly studied and presented. According to the ratio of wind speed at the height of bridge deck in the terrain model to the gradient wind speed of the wind field in front of valley model, a method of calculating design wind speed of bridge by the ratio and actual gradient wind speed in front of the valley was proposed. Test results in wind tunnel show that the mean wind speed profile in valley changes along the bridge span, and it cannot be simulated as a uniform wind speed profile. The attack angle at the bridge deck altitude is higher than the scope of ± 3° prescribed by the code and when considering the magnification effect of wind speed in valley, the height of measuring point and the shape of mountain on both sides should be taken into account.

关 键 词：山区峡谷 桥址 地形模型 风洞试验 风场特性 

分 类 号：U442.4[建筑科学—桥梁与隧道工程]