粗糙节理剪切性质的颗粒流数值模拟

在二维颗粒流程序PFC2D中生成粗糙节理剖面并模拟其剪切性质。通过数值直剪试验，从细观角度观察节理的宏观破坏过程。作为模型试验的一种补充，可以观测到粗糙表面微凸体的剪切破坏及微裂隙发育的情况。宏观剪切区域的产生主要是由细观剪裂纹的累积形成的，剪切破坏区域集中在爬坡效应显著的位置，即剪切应力集中的区域，剪切过程中形成的剪裂纹的数量在出现剪切峰值应力后显著增加，此时粗糙节理面的破坏最为显著。颗粒流数值试验能较好地再现模型试验的结果，采用PFC2D数值试验能部分替代真实岩石试样的模型试验，将其作为一种预测真实岩石节理抗剪强度的手段，从而解决天然粗糙节理形貌难以重复的问题。

PARTICLE FLOW NUMERICAL SIMULATION FOR SHEAR BEHAVIOR OF ROUGH JOINTS

Real rough joints profile has been rebuilt by PFC2D(particle flow code in 2 dimensions) successfully，and a series of PFC2D numerical simulation direct shear tests have been done to obtain its shear behavior. We can observe the failure process from the viewpoint of mesomechanics through PFC2D. The damage process of asperities on rough surface and the corresponding micro-fracture development can also be monitored in the numerical direct shear tests and these can be treated as a supplement of model tests. Macroscopic deformation of the sample is formed by the accumulation of mesoscopic shear cracks；and the shear failure area of rock mass mainly grows on the climbing slope of joint，where is the shear stress focus area as well. As the peak shear stress appears，the number of shear cracks is increasing quickly，when the failure of rough rock joint is most significant. According to the numerical tests，the results between model tests and numerical tests fit well；so real rock-joint model tests can be partly replaced by PFC2D numerical tests，which can become a way for forecasting the shear strength of real rock joints. The problem that the topography of real rough rock joints is hard to be restored has been solved by the numerical simulation method.