片麻岩破裂演化机制的颗粒流模拟研究

Numerical Simulation Research on Mechanism of Gneisses Fracture Evolution by Particle Flow Code

以杏山铁矿-45水平为工程研究背景,运用颗粒流理论,建立了片麻岩颗粒流数值模型;在分析区域岩体粒径分布规律和岩石物理力学特性的基础上,进行了PFC模型参数对宏观参数的敏感度分析,确定合理的模型输入参数;采用PFC2D程序,对片麻岩的单轴压缩试验进行了数值模拟。将模拟结果与室内试验结果进行对比,借助声发射技术,分析单轴压缩试验中岩石从微观裂纹到宏观破裂的演化过程,获得单轴压缩条件下岩石破裂的演化规律及破裂模式。研究结果对完善岩体的本构模型具有一定参考价值。

With the project background of Xingshan Iron Mine at -45 m level, the gneisses numerical models are constituted, in which the PFC （ particle flow code） theory is introduced. Based on the analysis of distribution law of rock particle diameter and physical and mechanical characteristics of the rock, a sensitivity analysis on macro parameters is carried out to determine the model input parameters ; the Uniaxial compression tests of gneisses sample are simulated by PFC2D. Compared with the indoor test results, with the help of acoustic emission, the rock fracture evolution rule and failure mode under the condition of uniaxial compression can be obtained through the evolution process of tiny crack towards to macroscopic crack. Some laws of rock fracture are discovered, which will be referential to develop rock constitutive models.