考虑地层变异特征一致性的围岩变形不确定性分析

目前地层变异性分析大多基于地层重复性沉积和变异特征一致性假设，而未考虑地质构造和风化作用的影响，忽略了地层变异性特征一致性的检验。为此，提出地层变异特征一致性的检验和分区方法，采用岩土相局部状态转移概率矩阵的相关系数作为一致性的定量判据，基于耦合Markov链模型模拟地层分布，并通过Monte Carlo方法分析隧道围岩变形的不确定性。利用青岛轨道交通某斜井的地质钻孔数据，探讨了地层变异特征一致性对地层分布和变形模拟精度的影响，分析了所提方法的有效性。结果表明，当地质构造和风化作用导致地层变异特征不一致时，增加钻孔数量无法提高地层分布模拟精度，采用所提方法对地层变异特征一致性检验并分区后，可避免状态转移概率矩阵中局部地层分布特征缺失的问题，提高围岩变形不确定性分析的准确性。

Uncertainty analysis of tunnel surrounding rock deformation considering consistency of geological heterogeneity features

Most analyses of geological heterogeneity are based on the assumption of repetitive deposition and stationary transition probabilities. However, the effects of tectonism and weathering are ignored, which leads to the absence of consistency verification of geological heterogeneity features (GHFs). A test method for the consistency of GHFs is herein proposed, as well as a partition method to detect stationary Markovian zones. The correlation coefficients between local transition probability matrices are adopted as quantitative criteria of consistency. The stratigraphic distribution is simulated by the coupled Markov chain model, and the deformation analysis of surrounding rock uncertainty is accomplished through Monte-Carlo simulations. Taking advantage of the borehole data in Tsingtao, the effect on stratigraphic distribution and uncertainty analyses induced by the consistency of GHFs is discussed, and the effectiveness of the proposed method is illustrated. The results indicate that the accuracy of uncertainty analyses cannot be improved with increased number of boreholes when there are conflicting GHFs. After the consistency verification of GHFs and the partition of stationary Markovian zones, the absence of local features can be avoided to improve the accuracy of uncertainty analyses of surrounding rock deformation.