极值风速变异系数的计算分析

Calculation and Analysis on Variation Coefficient of Extreme Wind Speed

推导了直接根据不同重现期极值风速计算变异系数的表达式;基于公路桥梁抗风设计规范列出的重现期系数,校准得到极值风速变异系数约为0.13;根据几座大桥桥位和规范提供的不同城市极值风速,采用变异系数表达式计算得到其分布在区间(0.1,0.35)内.分析结果表明,规范提供的重现期系数存在一些矛盾;极值风速变异系数与高度无关;根据不同重现期极值风速计算得到的变异系数的稳定性,可以评估极值风速的精度和可靠性.

The expression for calculating the variation coefficients of extreme wind speed is deduced according to different recurrent extreme wind speeds. Based on the recurrence coefficients included in the wind-resistant design specification for highway bridges, the variation coefficient of extreme wind speed is calibrated to be about 0.13. According to the extreme wind speeds of several bridge sites and different cities listed in specification, the variation coefficients are calculated by the deduced expression. The variation coefficients distribute in interval （0.1,0.35）. The analytical results reveal that the recurrence coefficients listed in the specification are inconsistent. The variation coefficient of extreme wind speed is irrelevant with height. The precision and reliability of the extreme wind winds may be estimated by the stability of the variation coefficients calculated by different recurrent extreme speeds.