In this study, the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities. The experimental results indicate that the evolutions of wave velocities became progressively anisotropic under uniaxial loading due to the direction-dependent development of micro-damage. A wave velocity model considering the inner anisotropic crack evolution is proposed to accurately describe the variations of wave velocities during uniaxial compression testing. Based on which, the effective elastic parameters are inferred by a transverse isotropic constitutive model, and the evolutions of the crack density are inversed using a self-consistent damage model. It is found that the propagation of axial cracks dominates the failure process of brittle rock under uniaxial loading and oblique shear cracks develop with the appearance of macrocrack.

在这项研究中，通过连续实时测量波速，研究了典型脆性岩石在单轴压缩下的微破坏过程和破坏机理。实验结果表明，由于微损伤的方向相关性发展，在单轴载荷下波速的演化逐渐各向异性。提出了一种考虑内部各向异性裂纹演化的波速模型，以准确描述单轴压缩试验中波速的变化。在此基础上，通过横向各向同性本构模型推断有效弹性参数，并使用自洽损伤模型对裂纹密度的演化进行反演。