Study on Experiment of Coal and Rock Adsorbed Gas Speciality Under Axial Load Role

In order to reveal the coal and rock structure variation law under the joint role of the stress and gas adsorption, a CT scanning was conducted on the coaI samples under the conditions of the different axial loading and different gas pressures. Based on the CT images, the voxel porosity a was defined and the volume strai n of the coal samples, CT image grey scale and pore distribution variation law were analyzed. the results showed that the voxel porosity a could reflect the different siz e pore structure variation within the coal samples under the joint role of the stress and gas adsorption. When 0 < as 20%, the voxel region in the gas role would play a | eading role. When a > 40%, the voxel region would mainly play a role of gas migration channel. Gas adsorption would firstly occur in the 0 < a S10% voxel region and w ith the axial pressure increased, the adsorption would steadily play a role to the 10% < as20% voxel region. Compared to the gas adsorption, the stress would have a C hange role to the pore structure of the coal samples remarkably.