基于广义Hoek-Brown准则的节理岩体强度及变形参数随机分析

Stochastic analysis of strength and deformation parameters of jointed rock mass based on generalized Hoek-Brown criterion

以赞比亚穆利亚希露天矿边坡为工程背景,在岩石力学试验以及现场勘察测绘数据的基础上,构建了以岩石单轴抗压强度、岩石质量指标和节理调查统计数据为输入参数的概率统计模型,并采用卡方检验对模型进行了吻合度检验。在广义Hoek-Brown准则的基础上,利用MATLAB编程及蒙特卡洛随机分析方法,由输入参数模拟获取节理岩体强度及变形参数的概率分布,得到各参数的取值范围(最小值/最大值)以及平均值、标准差等统计值。采用斯皮尔曼等级相关系数分析了强度及变形参数与各输入参数之间的相关关系。结合边坡工程实例,从破坏概率角度评价了该边坡工程的稳定性状态。该方法可充分考虑节理岩体参数的不确定性和变异性,可为实际工程安全决策提供重要的参考依据。

Uniaxial compressive strength, rock quality designation （RQD） and statistics data of joints survey are used as input parameters to construct probabilistic models based on mechanical tests and field surveying data from Muliashi Open Pit. These probabilistic models are well fitted by using the chi-square test. From the generalized Hoek-Brown criterion, the probabilistic distributions of strength and deformation parameters of jointed rock mass are obtained by using the stochastic analysis in the MATLAB program and Monte Carlo method. Spearman＇s rank correlation coefficient is applied to analyze the correlations between strength parameters and each input parameters. Based on the practical slope engineering, the slope stability is evaluated from the perspective of failure probability. The proposed method comprehensively considers the uncertainty and variability of jointed rock mass parameters, and can provide a valuable reference for safety decisions of practical engineering projects.