Probability distribution characteristics of extreme wind pressure for large span roofs

Probability distribution characteristics of extreme wind pressure for two kinds of typical large span roofs-a spherical shell and a cylindrical shell were analysed systematically. Based on the wind pressure samples obtained from more than 1000 independent runs of wind tunnel tests and the generalized extreme value theory, the probability distribution model of extreme wind pressure was established. The study indicates that the generalized extreme value distribution is the ideal model to describe the probability distribution of extreme wind pressure. The extreme wind pressures in most areas follow type III distribution, while few in downwind part follows type I and type II distribution. The extreme pressures which follow type II distribution show larger discreteness. The reliability of traditional peak factor method was examined and the results indicate that the peak factor method underestimates the unfavorable negative pressure in type II distribution area, with a error ratio between 20%~30%. The probability analysis method could determine distribution of extreme wind pressure with a certain guaranty rate and can thus be used to estimate local extreme wind pressure reasonably. ©, 2015, Science Press. All right reserved.