Coupling of stress and gas pressure in dual porosity medium during coal seam mining

In the process of coal seam mining, stress and gas pressure are two important parameters for the occurrence of gas disasters. Although many scholars have studied the parameters evolution during mining, the coupling of the parameters and the comparative analysis of gas pressures distributions in the matrix and fractures are rare. Here, the spatial distribution of stress and gas pressures during mining are simulated. The results illustrate that the stress, matrix and fracture gas pressures all exhibit a distressed zone, a concentration zone and an original zone with increasing distance from the coal wall of the working face. However, the change of gas pressures occur before the change of stress, and the peak gas pressure in the matrix is obviously higher than that in the fracture, so it is necessary to pay attention to the role of matrix gas pressure during mining to prevent the occurrence of gas outburst accident. (C) 2020 Published by Elsevier B.V.