边坡可靠性分析中g-line失效域及Copula优度评价研究

发布时间：2018-06-19 15:37

本文选题：Copula + 均质边坡　；参考：《岩土工程学报》2017年08期

【摘要】：针对岩土体抗剪强度参数联合分布模型中Copula优度评价问题,借助g-line给出了一种边坡失效域的抗剪强度参数表征方法,并利用积分途径得到了不同Copula及不同安全系数条件下算例边坡的失效概率,以此探讨了不同Copula计算结果的差异性,重点分析了S_n(p_c)、AIC、RMSE及Bias指标下各Copula的评价效果,并以上述各指标值为评价对象,分别计算了各Copula的熵权系数,从而给出了一种加权组合的Copula形式。结果表明,二次多项式拟合g-line的效果良好,此时边坡失效域可由抗剪强度参数独立表征;常用的评价指标得出的最优Copula结果不唯一,当不能有效地识别最优Copula时,可采用加权组合的Copula进行可靠性分析,能减小计算误差,有效地消除不同Copula引起的失效概率差异性,也能避免因直接采用某些Copula而引起的对边坡可靠度偏保守或者过高估计的问题。
[Abstract]:Aiming at the evaluation of Copula's degree of excellence in the joint distribution model of shear strength parameters of rock and soil, a method of describing the shear strength parameters of slope failure region is presented by means of g-line. The failure probability of slope under different Copula and different safety factors is obtained by integral method, and the difference of calculation results of different Copula is discussed, and the evaluation effect of each Copula under the index of Snnn PcCU AICRMSE and Bias is analyzed emphatically. The entropy weight coefficients of each Copula are calculated by taking each index value as the evaluation object, and a kind of Copula form of weighted combination is given. The results show that the quadratic polynomial fits the g-line well, and the failure region of slope can be independently characterized by shear strength parameters, and the optimal Copula results obtained by the commonly used evaluation indexes are not unique, when the optimal Copula can not be effectively identified, The reliability analysis of Copula with weighted combination can reduce the calculation error and effectively eliminate the difference of failure probability caused by different Copula. It can also avoid the problem of conservative or overestimated slope reliability caused by the adoption of some Copula directly.
【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;
【基金】：水利部公益性行业科研专项经费项目(201401029) 国家自然科学基金重点项目(51439003)
【分类号】：TU43

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