极值动态新Ⅰ型分布函数的模型及在汕头抗风防灾上的应用

NEW MODEL FOR A DISTRIBUTION FUNCTION WITH VARIABLE PARAMETER BASED ON ESTREME VALUE OF I TYPE AND ITS APPLICATION IN WIND-EXCITED HAZARD MITIGATION IN SHANTOU

最大风速分布函数的选择是抗风减灾的重要因素,迄今为止国内外所有可选择的分布函数,虽然对一个国家一些城市是好的,但是对另一些城市却不好,好的城市中,拟合优度准则检验结果也不能达到最佳位或趋近为1.本文采用动态的观点,根据不同城市的数据可用不同的参数值,使其可达到优度最佳值或趋近为1,在此思想基础上,改进了现在国内外绝大多数国家规范所采用的极值Ⅰ型,成为极值动态新Ⅰ型,是对分布函数选择彻底改革的一次尝试。按此原理,对汕头1959～1993共35年最大风速数据进行了分析,对各种概率条件下的风速风压提出了应用的数值。

Selection of distribution function of maximum wind-speed is very important for mitigation of wind-excited hazard. Up to date, althouth anyone of distribution functions that had been selected in calculation of maximum wind-speed, is suitable for most of cities in a country, but for the rest of cities, this distribution function selected is not good. Moreover, for anyone of distribution functions selected, probability examination function pe(λ) for optimum rule doesn't approach to best value. In this paper, a new probability distribution function with variable parameter in term with wind-speed, based on Extreme Value of I Type, is presented. According to the data of wind-speeds of an appointed city and based on selection for variable parameter by computer, an optimum probability distribution function can be obtained. In general, the probability examination function can reach to best value using this new function. For application, based on this new probability distribution function P(VC), maximum wind-speeds or wind-pressures of Shantou city for variable guarantee probability have been suggested in mitigation of wind-excited hazard.