岩石结构面直剪力学特征的颗粒流宏细观分析

Macroscopic and microscopic analysis of particle flow in direct shear mechanical characteristics of rock structural surface

目前,由于颗粒尺寸和位置随机分布而产生的粗糙度,导致在模拟过程中出现应力集中现象,从而无法利用PFC2D准确模拟岩石结构面的剪切力学行为。为了避免以上弊端,采用结构面两侧颗粒组接触判别法分别对倾角为20°和30°的三角形单锯齿结构面进行不同法向应力下的直剪模拟。模拟结果与物理试验结果基本吻合,表明此模拟方法可以真实模拟岩石结构面剪切力学行为。为了进一步验证此模拟方法在天然结构面模拟试验中的可行性,利用PFC2D对Barton标准十条节理轮廓线模型进行不同法向应力下的直剪试验,模拟结果与理论值吻合,表明模拟方法具有可行性,为剪切破坏过程和机理分析提供可靠的理论依据,为研究粗糙结构面强度特征提供了一种思路。

At present,the roughness resulting from the random distribution of particle sizes and positions causes the phenomenon that stress concentration occurs in the simulation process,making it impossible to simulate the shear behavior of structural surfaces of rocks accurately when we use PFC2D in numerical simulation.In order to avoid this defect,we use the method of particle group contact discrimination on both sides of the structural surface to respectively simulate the direct shear simulation of the triangular single serrated structural surfaces with inclination angles of 20 degress and 30 degress under distinct normal stresses.The result is consistent with the experimental result basically,demonstrating that this simulation method can truly simulate the shear behavior of rock structural surfaces of rocks.In order to further verify the feasibility of this simulation method in the simulation test of natural structural planes,we use PFC2D to conduct direct shear tests on the ten-standard-joint profiles model proposed by Barton under different normal stresses.The simulation result is consistent with the theoretical values,suggesting that the simulation method is feasible to provide a reliable theoretical basis for the shear failure process and mechanism analysis and to provide a way of thinking for the study of the strength characteristics of rough structural surfaces of rocks.