Copula理论下基于g-line失效域的边坡可靠性分析

发布时间：2018-03-29 21:11

本文选题：均质边坡　切入点：失效概率　出处：《岩土力学》2017年05期

【摘要】：针对边坡失效概率计算中功能函数难以确定、多重积分计算不便等问题,提出了Copula理论下基于g-line失效域的边坡可靠性分析方法。首先简要介绍了Copula理论,给出了基于Copula理论的边坡可靠性分析步骤,进而探讨了一般均质边坡的g-line曲线拟合形状及表征边坡失效域的抗剪强度参数范围,结果表明,二次多项式能很好拟合g-line曲线,内摩擦角和黏聚力可表征g-line曲线下的边坡失效域。以一均质边坡为例,通过在g-line失效域内积分,得出了3种Copula函数下边坡的失效概率,均与FORM及MCS法得出的结果比较接近,从而验证了Copula理论下基于g-line失效域的边坡可靠性分析方法的合理性。最后,讨论了不同Copula函数下失效概率计算结果的差异性随安全系数变化的特点,认为在低失效概率(高安全系数)时,可靠性分析结果对Copula函数类型比较敏感,应重视不同Copula函数类型引起的计算结果差异性及最优化问题的研究。
[Abstract]:In view of the difficulty of determining the function function in the calculation of slope failure probability and the inconvenient calculation of multiple integrals, a slope reliability analysis method based on g-line failure region based on Copula theory is proposed. Firstly, the Copula theory is briefly introduced. The procedure of slope reliability analysis based on Copula theory is given, and then the fitting shape of g-line curve of general homogeneous slope and the range of shear strength parameters representing the failure zone of slope are discussed. The results show that the quadratic polynomial can fit the g-line curve well. The internal friction angle and cohesive force can represent the slope failure region under the g-line curve. Taking a homogeneous slope as an example, by integrating in the g-line failure domain, the failure probability of the slope under three kinds of Copula functions is obtained, which is close to the results obtained by FORM and MCS method. The rationality of slope reliability analysis method based on g-line failure region based on Copula theory is verified. Finally, the difference of failure probability calculation results under different Copula functions with the variation of safety factor is discussed. It is considered that when the failure probability is low (high safety factor), the reliability analysis results are sensitive to the types of Copula functions, and the difference of calculation results caused by different Copula function types and the study of optimization problems should be emphasized.
【作者单位】：河海大学岩土力学与堤坝工程教育部重点实验室;三峡大学三峡库区地质灾害教育部重点实验室;武汉大学水利水电学院;
【基金】：水利部公益性行业科研专项经费项目(No.201401029) 中央高校基本科研业务费专项资金资助(No.2014B33714)~~
【分类号】：TU43

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