CT Test Analysis on Rock Breakage Mechanism Under Triaxial Loading-Unloading Condition

Using the rock mechanics test system RMT150 and high-resolution CT medical machine,the siltstone specimen CT scan tests under a constant confining pressure and different axial loadings were carried out and clear CT images of rock section were obtained.On the basis of the CT number's principle,a quantitative analysis on damage evolution and damage degree was performed.The micro-damage process of rock was reflected by the sample's 3D CT image reconstruction.The test study results showed as follows: The test rock specimen experiences three stages including compaction,expansion and destruction.The compression damage evolution of the rock is a long-time accumulation process and the crack generation and its expansion process manifest a sudden change,and there exists a 'density rebound' phenomenon in the region away from fracture plane.