基于离散元的岩石单轴压缩实验模拟及断裂特性分析

利用20 t级单轴实验机对大庆三肇地区深层岩石进行单轴压缩实验。基于室内实验力学得到岩石物理参数及单轴压缩所能测出的接触参数，通过离散元软件虚拟参数标定得到与室内实验相似力学性质的模拟岩石试样，并通过离散元软件EDEM对该岩石试样进行单轴压缩实验模拟，得到应力⁃应变曲线，通过对应力⁃应变曲线得到阶段性的破坏过程，研究了在单轴应力条件下岩石破坏的阶段性形态及微观的力链断裂特征及不同时刻黏结键数目与时间的关系。研究表明，在单轴压缩过程中脆性岩石没有较大的变形，力链断裂的方式为直接断裂，没有发生很大的形变。产生这种破坏的原因可能是岩石中裂隙的发生和发展的结果。

Experimental Simulation and Fracture Characteristics Analysis of Rock under Uniaxial Compression Based on Discrete Element Method

The uniaxial compression test of deep rock in three Zhaohe area of Daqing is carried out by using the 20 ton single axis test machine. Based on laboratory experimental mechanics, rock physical parameters and contact parameters can be measured by uniaxial compression. Simulated rock samples with similar mechanical properties as laboratory experiments can be obtained by calibrating virtual parameters of discrete element software. Uniaxial compression experiments of rock samples were carried out by EDEM simulation, and stress⁃strain curves were obtained. Based on the stress⁃strain curves, the staged failure process of rock under uniaxial stress was obtained. The staged failure morphology, micro⁃fracture characteristics of force chain and the relationship between the number of bond bonds and time at different time were studied. The results show that brittle rock has no large deformation during uniaxial compression, the mode of force chain fracture is direct fracture, and no great deformation occurs. The cause of this damage may be the result of the occurrence and development of cracks in rocks.