【摘要】 基于Bootstrap方法提出了一种堆石坝坝坡稳定可靠度分析方法.首先,介绍了一种堆石坝坝坡稳定可靠度分析方法;其次,运用Bootstrap方法对抗剪强度参数的边缘分布函数及表征相关性的Copula函数的统计不确定性进行了度量;最后,以糯扎渡水电站心墙堆石坝为例研究了边缘分布函数与Copula函数的统计不确定性对堆石坝坝坡稳定可靠度分析结果的影响规律.结果表明:基于抗剪强度参数试验数据估计的边缘分布函数与Copula函数具有较大统计不确定性;Bootstrap方法可以有效地模拟边缘分布函数和Copula函数的统计不确定性并将坝坡稳定失效概率表征为具有一定置信水平的置信区间;同时考虑边缘分布参数、边缘分布类型、相关系数与相关结构统计不确定性与仅考虑边缘分布参数与相关系数的统计不确定性相比将使失效概率具有更大变异性,且失效概率均值更大,忽略分布类型和相关结构的统计不确定性将高估堆石坝坝坡的实际稳定状况.更多还原

【Abstract】 This paper proposes a Bootstrap-based method for analyzing slope stability reliability of rockfill dams.Firstly,an analytical method for slope stability reliability of rockfill dams is introduced.Secondly,the statistical uncertainties of marginal distribution function and Copula function which characterize the correlation between shear strength parameters are measured by Bootstrap method.Finally,the influence of statistical uncertainties of marginal distribution function and Copula function on the slope stability reliability of rockfill dams is studied with Nuozadu dam as an example.The results show that the marginal distribution functions and the Copula functions estimated by original test data of shear strength parameters have great statistical uncertainty.Bootstrap method can effectively model these statistical uncertainties and use a confidence interval with a certain level to characterize the failure probability of rockfill dams.The failure probability considering the statistical uncertainties of marginal distribution parameters,marginal distribution type,correlation coefficient and correlation type will have greater variability and higher means than the answer considering the statistical uncertainties of marginal distribution parameters and distribution type.The actual stability of rockfill dams will be overestimated if ignoring the statistical uncertainties of distribution type and correlation type.更多还原