土体参数空间变异性对边坡失效模式间相关性及系统可靠度的影响

发布时间：2018-03-24 02:18

本文选题：边坡　切入点：空间变异性　出处：《岩土力学》2017年02期

【摘要】：常用的计算失效模式间近似相关系数存在一定的误差,采用Pearson相关系数准确地表征边坡失效模式间相关性。基于近似相关系数和Pearson相关系数,研究了土体参数空间变异性对边坡失效模式间相关性、代表性失效模式数目、边坡系统失效概率上、下限3方面的影响。简要介绍了选取边坡代表性滑动面的风险聚类法以及系统失效概率上、下限的Ditlevsen双模界限公式。以单层和两层边坡为例研究了近似相关系数的适用性。结果表明:常用的近似相关系数不能考虑土体参数空间变异性对边坡失效模式间相关性的影响,而Pearson相关系数能够有效地反映土体参数空间变异性对边坡失效模式间相关性的影响。当土体参数空间变异性较弱时,近似相关系数与Pearson相关系数间差别明显,基于近似相关系数会选取过多的代表性滑动面,不能有效地反映边坡代表性破坏模式。此外,基于近似相关系数计算的边坡系统失效概率上限会超过1,系统失效概率上、下限范围很宽,使得系统失效概率上、下限失去了意义。相比之下,基于Pearson相关系数计算的边坡系统失效概率上、下限范围较窄,能够有效地反映系统失效概率变化情况。
[Abstract]:There is a certain error in calculating the approximate correlation coefficient between failure modes. The Pearson correlation coefficient is used to accurately characterize the correlation between slope failure modes. Based on the approximate correlation coefficient and Pearson correlation coefficient, The correlation between the spatial variability of soil parameters and slope failure modes, the number of representative failure modes and the failure probability of slope system are studied. This paper briefly introduces the risk clustering method for selecting the representative slip surface of slope and the failure probability of the system. The applicability of the approximate correlation coefficient is studied by taking single-layer and two-story slopes as examples. The results show that the commonly used approximate correlation coefficients can not take into account the influence of spatial variability of soil parameters on the correlation between slope failure modes. Pearson correlation coefficient can effectively reflect the influence of spatial variability of soil parameters on the correlation between slope failure modes. When the spatial variability of soil parameters is weak, the difference between approximate correlation coefficient and Pearson correlation coefficient is obvious. Based on the approximate correlation coefficient, too many representative sliding surfaces will be selected, which can not effectively reflect the representative failure mode of slope. In addition, the upper limit of failure probability of slope system calculated based on approximate correlation coefficient will exceed 1, and the failure probability of slope system will exceed 1. The lower limit range is very wide, which makes the system failure probability higher and lower bound meaningless. Compared with the slope system failure probability calculated based on Pearson correlation coefficient, the lower limit range is narrower, which can effectively reflect the change of system failure probability.
【作者单位】：武汉大学水资源与水电工程科学国家重点实验室;武汉大学水工岩石力学教育部重点实验室;
【基金】：国家杰出青年科学基金项目(No.51225903) 国家自然科学基金项目(No.51329901,No.51679174) 湖北省自然科学基金创新群体项目(No.2014CFA001)~~
【分类号】：TU43

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