山区峡谷桥梁设计基准风速的确定方法

为向山区桥梁设计提供重要参数,以某大跨度悬索桥为工程背景,在缺少桥址风速数据的情况下,利用桥位附近气象站资料,用气象学分析法计算出桥位处逐年最大风速;分别用极值Ⅰ型法和虚拟气象站法计算出桥位100年一遇最大风速;比较2种方法的计算结果,并偏安全地取较大值作为桥址基本风速;最后,通过地形修正,以得出桥梁设计基准风速.结果表明:气象学分析法比虚拟气象站法计算的桥梁设计基准风速小;在缺少桥位风速的情况下,宜采用虚拟气象站法计算出的桥梁设计基准风速. 

Determination Method for Basic Design Wind Speed of Mountainous-Valley Bridge

In order to provide a valuable parameter for the design of mountainous-valley bridges, a long-span suspension bridge was taken as an engineering example. Under the circumstance of lacking wind speed data at the bridge site, based on meteorological stations' statistics around the bridge site the meteorology analysis method was applied to calculate the maximum wind speed. The extreme-value type I method and the virtual standard weather station method were respectively adopted to calculate 100-year maximum wind speed at the bridge site, the two calculated results of 100-year maximum wind speed were compared, and the bigger one in the two results was selected conservatively as the basic wind speed at the bridge site. At last, the basic design wind speed was determined by topographic correction. The research results show that the basic design wind speed at the bridge site calculated by the meteorology analysis method is smaller than that calculated by the virtual weather station method, so under the condition lacking statistics of the wind speed at the bridge site, the basic design wind speed based on the virtual weather station method should be adopted as the basic design wind speed.