大跨开合式屋盖峰值风压的试验研究

Peak factors of extreme wind pressure on a retractable stadium roof

以1:300的几何缩尺比制作了一个开合式大跨屋盖体育场的刚性模型,在B类地貌中对该体育场进行了同步测压风洞试验。对活动屋盖开启和关闭工况下的屋盖表面净风压时程的随机特性进行了研究,结合概率曲线相关系数法对屋盖净风压时程在Gumbel、R-Weibull、Normal和Gamma四种候选分布中选择了最恰当的Gamma和Normal分布来描述测点的风压系数概率分布,进一步采用了转换过程法对屋盖测点的极值风压峰值因子进行了估计,并给出了极小值风荷载分布。结果表明:①转换过程法可以较好考虑风压的非高斯特性,能更安全地估计开合屋盖测点的极值风压;②固定屋盖的极值风压峰值因子在活动屋盖开启工况要稍大于活动屋盖关闭工况,其位置主要在固定屋盖屋顶口;活动屋盖极值风压峰值因子则开启工况小于关闭工况。③对于峰值风压,由于关闭工况下较大的平均风荷载,其极小值风荷载总体上仍大于活动屋盖开启工况。

A retractable roof stadium rigid model was made with a scale of 1:300,and wind tunnel tests were carried out to measure the wind pressures on the roof in category type B.The stochastic characteristics of the wind pressures were particularly studied,using the probability plot correlation coefficient method to find out the optimum marginal probability distributions:Gamma distribution and Normal distribution to fit the distribution of wind pressures coefficients on the roof.A standard translation processes approach was introduced to estimate the peak factors.The calculation results showed that (1) the non-Gaussian characteristics of wind pressures on the retractable stadium roof can be taken into account,this method can be used to estimate the extreme pressure coefficients more safely ;(2) on the fixed roof,when the retractable roof is opened,the total extreme pressure coefficients are lightly larger,most locate on the top of the fixed roof,but on the retractable roof the extreme pressure coefficients are smaller.