低应变率下岩石内部裂纹演化的X射线CT方法

X射线CT方法研究发现单轴压缩条件下岩石经历压密、扩容、CT尺度裂纹演化和破坏过程4个阶段。这表明低应变率条件下岩石的变形破坏过程的细观机制主要表现为裂纹成核、萌生、扩展、贯通过程。CT图像分析和密度损伤增量分析是X射线CT方法的两种手段。CT图像分析可以获得裂纹宽度、长度、方位等定量化参数。密度损伤增量分析可以获得密度损伤增量图像和岩石试件内部任意应力状态、任意部位的密度损伤值。在CT尺度裂纹演化和破坏阶段，由于岩石损伤高度局部化，声发射率参数不能精确反映岩石破坏的细观机制。

X-RAY CT APPROACH ON ROCK-INTERIOR CRACK EVOLUTION UNDER LOW STRAIN RATE

By X-ray CT method,it is found that rock experiences condensation,dilatancy,evolution of CT crack and rapture process in turn under uniaxial compression,which shows the meso-mechanism of rock deformation and rapture. CT image analysis and density damage increment analysis are two approaches based on X-ray CT. Through CT image analysis,the width,length and direction of crack are gained. The values of density damage at any stress state and position are gained by analysis of density damage increment. At the process of CT crack and rapture evolution,the acoustic emission can not precisely reflect the meso-mechanism of rock deformation and rapture because of localization of damage.