不规则砂岩的三维模型数字重构及其破裂过程研究

Study on Three-Dimensional Model Digital Reconstruction and Fracture Process of Irregular Sandstone

以烂泥沟金矿为工程背景,基于数字图像处理及破裂过程分析程序对不规则砂岩进行三维模型数字重构,模拟单轴压缩作用下不规则砂岩的真实细观非均质力学模型的失效机理及破裂过程;研究了不同颗粒粒径及不同内部结构砂岩的破裂过程及力学特性。结果表明:不规则试件在单轴压缩条件下破裂模式由单裂纹向多裂纹转变,裂纹方向与主应力方向成一定夹角;随着应力的增加,试件内部拉伸破坏单元的产生、发育、贯通导致试件形成宏观剪切破裂带;岩石试样在破裂过程中释放的大部分能量来自于高应力区的破碎带。此外,在模拟过中发现试件越趋于球形,应力-应变曲线线性行为越长,试件强度越大。研究结果对探讨矿岩破碎机理、寻找高效节能的破岩方式具有重要意义。

Taking Lannigou Gold Mine as the engineering background,based on the digital image processing and fracture process analysis program,the three-dimensional model digital reconstruction of irregular sandstone was carried out to simulate the failure mechanism and fracture process of the real mesoscopic heterogeneous mechanical model of irregular sandstone under uniaxial compression.The fracture process and mechanical properties of sandstone with different particle sizes and different internal structures were studied.The results show that the fracture mode of irregular specimens changes from single crack to multiple cracks under uniaxial compression,and the crack direction has a certain angle with the principal stress direction.With the increase of stress,the generation,development and penetration of the tensile failure unit inside the specimen lead to the formation of macroscopic shear fracture zone.Most of the energies released by the rock specimens during the fracture process come from the fracture zone in the high-stress area.In addition,during the simulation process,it is found that the more spherical the specimen tends to be,the longer the linear behavior of the stress-strain curve is,and the greater the strength of the specimen is.The research results are of great significance for exploring the mechanism of rock breaking and finding efficient and energy-saving rock breaking methods.