Abstract Since all available surrounding rock classification approaches don't consider the size effect of the tunnel excavation span and unfavourable geologic bodies, it’s impossible to evaluate the systematic stability of the surrounding rock by rock mass classification alone. In addition, the evaluation results usually have poor robustness because of the uncertainty of structural information. In this paper, the actual distribution information and probability distribution model of the joints in tunnel face are obtained. Many random numbers that meet the probabilistic distribution models can be produced by Monte carlo simulation, and many random rating values of these evaluation indices are also obtained. The distribution probability affiliated with different rock mass levels can be attained by inductive statistics, and a robust evaluation of surrounding rock classification is carried out. The deformation and failure process of surrounding rock are simulated based on the discontinuous deformation analysis. A comparison analysis of removable blocks and their distribution characteristics is carried out by UJN. The most likely damaged parts and rockfall styles are indicated, and a comparison between calculation result and practical collapse of Laohushan tunnel is carried out, which are nearly the same. The research results offer practical guidance for field construction and supporting optimization.

中文翻译：

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基于节理信息数字特征的超断面隧道围岩可靠稳定性分析

摘要 由于现有的围岩分类方法都没有考虑隧道开挖跨度和不利地质体的尺寸效应，仅靠岩体分类是无法评价围岩系统稳定性的。此外，由于结构信息的不确定性，评价结果通常鲁棒性较差。本文得到了掌子面节理的实际分布信息和概率分布模型。蒙特卡罗模拟可以产生很多满足概率分布模型的随机数，也可以得到很多这些评价指标的随机评分值。不同岩体层次的分布概率可以通过归纳统计得到，并对围岩分类进行了稳健的评估。基于非连续变形分析模拟围岩变形破坏过程。UJN 对可移动块及其分布特征进行了比较分析。指出了最可能损坏的部位和落石类型，并与老虎山隧道的计算结果和实际坍塌进行了比较，两者几乎相同。研究成果为现场建设和配套优化提供了实践指导。指出了最可能损坏的部位和落石类型，并与老虎山隧道的计算结果和实际坍塌进行了比较，两者几乎相同。研究成果为现场建设和配套优化提供了实践指导。指出了最可能损坏的部位和落石类型，并与老虎山隧道的计算结果和实际坍塌进行了比较，两者几乎相同。研究成果为现场建设和配套优化提供了实践指导。