Research on mesoscopic damage evolution mechanism of gas-bearing coal based on CT scanning with real time loading

To study the deformation and damage evolution characteristics of various structures and components in the loaded coal, the real-time loading computed tomography(CT) scanning test is carried out with outburst-risk coal, and a 3D reconstruction model is analyzed using meshless numerical simulation, and the damage evolution characteristics of coal are analyzed from the meso scale. The results show that: (1) minerals have two effects on the loading of coal due to their high elastic modulus and low Poisson’s ratio; 2) as load-bearing components, minerals and coal also affect the direction of stress. Due to the high strength of minerals, the influence degree is higher than that of coal; (3) The displacement of the loaded coal decreases as it approaches the bottom, and the internal displacement also increases or decreases with the distribution of minerals and fractures; (4) The gas bearing coal itself is weakened by the effect of gas. Under the action of external load, there will be stress concentration, inconsistent displacement of each component, stress exceeding the strength limit, etc., so the damage and failure process is the result of comprehensive action. The results of this study have a theoretical value for the prevention and control of coal and gas outburst.