随机形貌岩石节理剪切-渗流数值模拟和剪胀-渗流模型

采用Hurst指数的独立分割方法构造随机形貌岩石节理剖面，基于岩石节理的CY模型构建随机形貌岩石节理剪切-渗流计算模型和数值分析方法，为研究岩石节理的剪切-渗流响应提供了理论参考。采用CY微段节理模型的细观剪切力学参数，探讨剪切作用下随机形貌岩石节理剪切-渗流响应。结果表明：节理粗糙度越大，岩石节理的宏观剪切峰值强度和剪胀角随之增大；随着法向应力的增加，节理的剪胀效应逐渐减弱；剪切过程中的节理渗透系数呈平稳增长-快速增大-渗流稳定3阶段变化，在剪切最开始短暂时候，节理剪缩使渗流偏离立方渗流准则，节理渗透系数与法向应力具强耦合关系。引入剪胀等效节理水力隙宽，建立岩石节理的非线性剪胀-渗流模型，合理地描述了不同粗糙度节理剪切过程中的剪胀效应及其对节理渗透系数的贡献。

Shear-seepage numerical simulation and shear dilatancy-seepage model of rock joint with random morphology

The rock joints profile with random morphology was constructed by using independent segmentation method of Hurst exponent.Based on CY model of rock joints，the shear-seepage calculation model and numerical simulation method of rock joints with random morphology was established.The rock joints profile with random morphology provides theoretical basis for studying shear-seepage response of rock joints.Adopted the micro shear mechanical coefficients of CY micro-segment model，the shear-seepage response of rock joints with random morphology was discussed.It is concluded that both the macro shear peak value and dilatancy augment with the increasing of rock joint’s roughness；With the normal stress increasing，the corresponding dilatancy effect dwindles gradually；During shearing process，the permeability of rock joints presents three phases：steadily increasing，quickly increasing，seepage stability.At the initial moment of shear，the seepage deviates cubic seepage criterion because of negative dilation in rock joint，the permeability of rock joint represents strong coupling relation with normal stress.By introducing equivalent joint hydraulic aperture of shear dilatation，the nonlinear shear-seepage model of rock joint was established，the dilatancy effect and its contribution to permeability of rock joints were rationally described during shearing process when the roughness of rock joints were different.