考虑三维形貌参数的结构面峰值剪切强度 预测新模型

A New Prediction Model for Peak Shear Strength of Rock Joints Considering the 3D Morphology Parameters

为进一步修正Grasselli结构面三维形貌参数系统,获得一个能够反映结构面剪切机理的预测模型.深度分析视倾角和分布参数,提出单值分布函数A*θ*,并将其作为权重函数参与平均视倾角的计算;定义相对分布参数C*,揭示了分布参数对结构面抵抗剪切的控制作用;最后,提出一个新的峰值剪切强度预测模型,利用国内外学者发表的50组数据验证,新模型相较于Grasselli系模型的预测精度最佳.另外,定义了分布参数C的物理和数学边界,从理论上解释了实验值不小于1的现象,总结了视倾角的分布规律和初始剪胀角的构成,将Grasselli系模型从理论上划归至统一形式.新的预测模型参数更为简洁,物理意义和数学定义明晰,同时能够较好地揭示结构面的剪切机理.

The apparent dip angle and the distribution parameter are camprehensively analyzed to correct Grasselli’s 3D morphology parameters system as well as get a new prediction model reflecting the shear behavior of rock joints.The single-valued distribution function A*θ*is used as the weight function to calculate the average apparent dip angle.By defining the relative distribution parameters C*,revealing the control function of distribution parameters on resisting shear.A new peak shear strength prediction model is proposed.Compared with Grasselli’s model,the prediction accuracy of the new model is better verified through 50 sets of published data.The physical and mathematical boundary of distribution parameter C is proposed,and the phenomenon that the value of C from experiments is not less than 1 is explained.The distribution law of apparent dip angle and the composition of initial dilatancy angle are summarized,and the Grasselli’s model is classified into a unified form.The new prediction model has concise parameters,clear physical meaning and mathematical definition,and reveal the shear mechanism of rock joints.