考虑台风持时效应的低矮房屋围护结构风灾损失分析

Wind hazard analysis of low-rise building envelopes considering typhoon duration effect

低矮房屋围护结构在台风中往往破坏严重,有效预测台风周期内低矮房屋围护结构的风致损失具有重要意义。文章基于风洞试验数据,围绕台风持时低矮房屋围护结构风灾损失分析方法开展研究。首先阐述台风周期内低矮房屋的风致破坏过程,回顾现有考虑台风持时效应的风灾损失一般分析方法;在此基础上,通过对风灾损失的逐步分析法中模拟策略进行改进,提出考虑台风持时效应的低矮房屋围护结构风灾损失估计高效分析方法;其中,采用半经验公式估计非高斯风压极值分布,并基于Nataf变换建立风压的多元极值联合概率模型;结合台风实测数据,对方法进行演示。研究发现,低矮房屋围护结构在台风中的破坏随着时间推移逐渐累积,考虑台风的持时效应十分必要;使用该方法可以有效地考虑围护构件荷载的非高斯性、随机性以及空间相关性等影响因素,且计算效率大幅提升。

Low-rise building envelopes are often severely damaged in typhoon hazards.Predicting damage of low-rise building envelope during the typhoon is important for disaster prevention.The paper proposes a database-assisted method to perform the hazard analysis on low-rise building envelope with consideration of typhoon duration effects.The damage process of low-rise buildings during the typhoon is firstly depicted.The general method of wind hazard analysis in typhoon duration is reviewed.Based on the former method,a highly efficient method of wind hazard analysis of low-rise building envelopes in typhoon duration is developed by improving the simulation strategy in the step-by-step method.The semi-empirical formulas are presented to estimate extreme value distributions of non-Gaussian wind pressures and joint probability distribution of multivariate extreme values is then established with Nataf transformation.An existing typhoon is employed to illustrate the proposed method.It is found that damage of building envelope is cumulative with passage of typhoon,so it is necessary to consider typhoon duration effects.Influence factors,such as non-Gaussianity,randomness and spatial dependence of wind loads,can be well considered in the developed method and the computation efficiency is greatly improved.