Lévy稳定分布对住宅楼面活荷载的统计分析
STATISTICAL ANALYSIS OF LIVE LOAD ON RESIDENCE FLOOR USING LÉVY STABLE DISTRIBUTIONS
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摘要: 该文基于Lévy稳定分布, 给出了设计住宅楼面活荷载标准值的一种新的统计方法. 该方法分为4个步骤, 首先采用Lévy稳定分布, 拟合楼面活荷载的累积分布函数;然后运用Lévy随机数, 模拟设计基准期内活荷载的极大值分布;其次通过设定活荷载极大值分布的分位数, 计算持久性活荷载和临时性活荷载的最大值;最终以赋权重的方式, 确定楼面活荷载的标准值. 我们的分析结果表明, 这个新方法不需要大量的调查数据, 避免了Turkstra荷载组合原则基于经验确定标准值的缺点. 与极值I型分布和威布尔分布相比, Lévy稳定分布的模拟精度最高, 并且其参数能够直接刻画活荷载分布的非对称性和拖尾性. 此外, 采用Lévy随机数模拟法, 数学简单, 方便工程技术人员的使用.Abstract: Based on Lévy stable distributions, this paper develops a new statistical approach for residence-floor live-load design. The approach involves fours steps: firstly using Lévy stable distributions to fit the cumulative distribution function of live loads, secondly employing Lévy random numbers to determine the maximum distribution of live loads, thirdly using the maximum distributions under a certain quantile to calculate the extreme values of sustained live loads and transient live loads, finally utilizing a weighted method to determine the characteristic value of live loads on a residence floor in a design reference period. Our analysis results show that this new approach does not require a large data set of survey live loads and also remedies the drawback in the empirical Turkstra load combination principle, which is used to determine the characteristic value. Compared with Type I extreme value and Weibull distributions, Lévy stable distributions have the best precision and its parameters can directly depict the skewness and heavy tail of live load distribution. In addition, the simulation method of Lévy random numbers is mathematically simple and easy-to-use for non-expert engineers.