基于UDEC节理岩体抗压强度的数值研究

通过对江西某矿区岩样进行岩石力学试验，得到岩石试件的力学参数，利用Hoek-Brown法估算岩体力学参数。基于分形理论，结合Monte Carlo方法生成节理岩体平面网络图，以岩体网络图中心为基点，选取节理岩体模拟试件，采用离散元软件UDEC开展节理岩体抗压强度的数值实验。结果表明：选取角度、围压相同时，随着岩体尺寸的增大，节理岩体各向异性减弱，抗压强度呈非线性减小趋势，并趋向于某一定值，可拟合为负指数变化关系；围压、尺寸相同时，随着选取角度的增大，节理岩体抗压强度呈微幅波动趋势，这应与节理分布的分形特性有关。取样角度（所截取的岩体试件与水平方向的夹角）为60°时，抗压强度值略高，节理岩体尺寸效应与围压效应也较为明显；选取角度、尺寸相同时，随着围压的增大，岩体各向异性减弱，抗压强度呈线性增大趋势。

Numerical Study of Joint Rock Mass Compressive Strength Based on UDEC

This thesis obtained the mechanical parameters of rock specimens through rock mechanics tests on a rock sample in a mining area in Jiangxi and applied the Hoek-Brown Criterion to estimate the rock mass mechanical parameters. Combining the fractal theory and the Monte Carlo method, a jointed rock mass network was generated, and jointed rock mass simulation specimens were taken by using the center of the jointed rock mass network as the base point. The discrete element software UDEC was used to stimulate the numerical experiment of the jointed rock mass compressive strength. The results show that controlling for the sampling angle and confining pressure, the increase in rock mass size correlates with the weakening of the anisotropy of the jointed rock mass. The compressive strength of the jointed rock mass shows a non-linear decrease trend and tends to a certain value, which can be fitted into a negative exponential change relationship; controlling for the confining pressure and size, the increase in the sampling angle will result in a slight fluctuation of the compressive strength of the jointed rock mass, which can be explained by the fractal characteristics of the joint distribution. The size effect and confining pressure effect of the jointed rock mass are more obvious when the sampling angle is at 60°, where the compressive strength value is slightly higher; when sampling angle and size are controlled for, as the confining pressure increases, the anisotropy of the rock mass weakens, demonstrating a linear increase in compressive strength.