动静组合荷载下岩石特性的三维数值模拟研究

Three-dimensional Numerical Simulation of Rock Dynamic Characteristics Under Static and Dynamic Loads

针对深部岩石工程中,围岩在动荷载压力作用之前就已经承受高静应力或地应力,因此对三维动静荷载联合作用下的岩石变形及破坏特性展开研究具有重要意义。为了探究三维动静组合加载下岩石的力学特性,采用FLAC3D数值模拟方法对岩样进行模拟,以岩石单轴抗压强度的0%、20%、50%和80%作为轴压值,分别设置0 MPa、2 MPa、4 MPa、6 MPa、8 MPa为围压进行加载。得出以下结论:在轴向静压固定、围压变化下,试件的组合强度逐渐升高;当对岩石试件的径向进行加载,增强岩石的整体强度,表现出等效应力逐渐变大;当围压不变,轴向静压变化的情况下,轴向静压值成为岩石试件毁坏程度和破碎速度的主要条件,当压力值增大到一定程度,试件将发生破碎。

In the deep rock engineering,the surrounding rock has been subjected to high static or ground stress before the dynamic load pressure.Therefore,it is of great significance to study the deformation and damage characteristics of rock under the combined action of three-dimensional static and dynamic loads.For the purpose of exploring the mechanical properties of rock under load in the three-dimensional static group,the rock was simulated with five methods using FLAC3D.The axial compressive values of 0,20,50 and 80 of the rock uniaxial compressive strength were set respectively,and the pressure was set up by 0 MPa,2 MPa,4 MPa,6 MPa,and 8 MPa respectively.The following conclusions are drawn:When the axial static pressure is fixed and the confining pressure is changed,the combined strength of the specimen is gradually increased.When the rock specimen is loaded,the overall strength of the rock is enhanced and the equivalent stress is increased gradually.When the confining pressure is constant and the axial static pressure changes,the axial static pressure value becomes the key factor of the damage degree and breaking speed.The main condition is that when the pressure increases to a certain extent,the specimen will be broken.