为研究高层建筑多风向风致加速度满足人体舒适度要求的可靠度,推导了以结构顶部加速度响应均方根值表征的近似解析表达式,建立了风速风向联合分布的概率模型。并以广州西塔高层建筑为算例,结合其工程气象分析及风洞试验等相关资料,通过随机振动理论和曲线拟合方法,得到其在主要风向角下风致顶部加速度响应均方根值与10m高度平均风速的拟合表达式。在此基础上,考虑平均风速服从Weibull分布,阻尼比服从正态分布条件下,基于条件概率,采用验算点法对此高层建筑在考虑风速风向联合概率分布情况下,满足重现期10年的顶部风致加速度响应(舒适度)要求的可靠度进行了分析,表明结构顶部重现期10年风致加速度失效概率在各方向有明显差别,说明考虑风速风向联合分布的风致结构舒适度失效概率计算的必要性。采用本文的验算点法对本算例高层建筑的可靠度分析,结果表明其对应重现期10年的考虑风速风向联合概率分布情况下满足舒适度要求的可靠度值达99.98%。
In order to evaluate the reliability of human-comfort of high-rise buildings under wind excitation, the approximate analytical formula of root mean squared (RMS) wind-induced acceleration of high-rise building top was deduced in this paper. The joint probability distribution model of wind speed and direction was established. Taking the Guangzhou West Tower as an example, the engineering meteorological analysis and wind tunnel test results for this super high-rise building were investigated. By adopting the curve fitting method and random vibration theory, the empirical formula of wind-induced acceleration response of this high-rise building can be expressed in terms of the mean wind speed at 10m above ground level, the natural frequency and damping ratio of the investigated building. Considering the mean wind speed as random variable with Weibull distribution, and damping ratio of the building as random variable with normal distribution, the reliability of human-comfort of tall buildings was evaluated by the check- point method in reliability theory. The combined effect of joint probability distribution of wind speed and direction on the reliability analysis of human-comfort of tall buildings was considered by adopting the conditional probability multiplication theorem. Analysis results show that the failure probabilities of wind-induced acceleration response in each wind approaching direction are obviously different. Therefore the joint probability distribution model of wind speed and direction should be included in the reliability analysis. The final analysis results also show that the reliability of wind-induced acceleration response (human-comfort) of the investigated high-rise building top can reach 99.98% under the wind excitation of design wind speeds with 10-year return period.