考虑风速变异性的风致屋面覆盖物损失评估

摘要

Roof coverings on the building roof are prone to damage in strong winds and their loss may cause larger damage to the building interior due to rainwater penetration.Hence this paper presents a probabitistic damage estimation procedure to predict roof covering damage in strong winds based on the wind pressure coefficient data collected from the wind tunnel test at the University of Western Ontario.Firstly,the wind tunnel test and the experimental data are briefly introduced.Secondly,Hermite polynomial model is used to estimate the probability density distribution of wind pressure coefficient for each measuring point.Furthermore,the translation process method is adopted to evaluate the probability distribution function of corresponding peak wind pressure coefficient.Finally,with the asphalt shingle as the example,the failure probability for each shingle and the damage ratio for the entire roof are determined,including the cases with and without consideration of the variability of mean wind speed.%屋面覆盖物在大风中容易遭到破坏,而屋面的破坏可能引起雨水渗透而导致房屋内部受到更大的损害.因此文章基于西安大略大学风洞试验数据提出一种在强风作用下屋面覆盖物风致损失的概率评估方法.首先简单介绍了风洞试验及试验数据的基本概况;然后利用Hermite多项式模型拟合每个测点的风压系数的概率密度分布;随后采用转换过程法估计相应的极值风压系数概率分布函数;最后以沥青瓦片为例,计算每块瓦片失效的概率及整个屋面覆盖物的损失率,包括不考虑风速变异性和考虑风速变异性的情况.