Experimental Research on Permeability Characteristics of Briquette Coal Containing Water Under Different Axial Loading Rates

In order to study the seepage characteristics of coal containing methane with different moisture content under the influence of mining, taking briquette coal as the research object, we use self-developed three-axis gas seepage test device to carry out the three-axis seepage test for coal containing gas with different axial loading rates and different moisture content. The results show that, under the loading conditions of fixed gas pressure and fixed confining pressure unloading rate, the axial loading rate is increased, and the coal sample seepage rate and coal sample permeability are non-linearly increasing; the permeability and seepage rate of coal samples under low moisture content increase largely with the increase of water content in the case of increasing the coaxial loading rate; under the condition of the same moisture content, the bigger of the increase amplitude of loading rate is, the larger of the increase amplitude of permeability and seepage rate is; at the same time, the relationship between moisture content and permeability is quadratic polynomial, and the higher the axial loading rate is, the higher the fitting degree is. Therefore, increasing the water content of coal seams can reduce coal and gas outburst risk.