工程设计极值风速取值方法的研究

Investigation of Selection Methods for Extreme Wind Speed in the Engineering Structure Design

极值风速的研究对于结构的安全取用和抗风设计有重要作用.通过海南某大跨斜拉桥抗风设计,对比研究了工程中常用的极值风速概率模型,包括极值Ⅰ,Ⅱ,Ⅲ型分布和皮尔逊Ⅲ型.针对不同的概率分布模型,对工程中常用的参数估计方法——矩法、最小二乘法、概率加权法以及变量替换法进行了对比研究.结果显示:用矩法进行参数估计的极值Ⅰ型分布是该地区的风速概率分布的最优曲线.最后,在此基础上对沿海台风多发地区大跨斜拉桥抗风设计提出了建议.

Investigation of extreme wind speed was important for the engineering safety access and wind-resistant design of structures.Through the wind-resistant design of the cable-stayed bridge in Hainan Province,methods to calculate extreme wind speed for the engineering design were described,including classical methods based on the generalized extreme value（GEV） and its three types Type Ⅰ,Ⅱ and Ⅲ and Type Pearson Ⅲ.Reasonable parameter estimation methods commonly used in projects were compared for different probability distribution models,like the method of moment,the least-square,et al.The results show that the method to estimate the parameters of extreme value type I distribution with the moment is the optimal curve of the region′s wind speed probability distribution.Finally,some proposals are given for the wind-resistant design on bridge in the typhoon-prone areas of coastal.