Influence Mechanism of Mine Pressure on Coal Seam Gas Emission During Mining

Gas is one of the main factors causing coal mine accidents in China. Understanding the mechanism of the influence of mine pressure on coal seam gas emission has important theoretical guiding significance for coal mine enterprises to be able to control gas. This paper chose the 72,909 working face in the Du’erping coal mine as the engineering background, analyzed the characteristics of the mine pressure in the working face and the driving face through numerical simulation, and found that the power of the gas emission in the working face is the mine pressure, while that of gas emission in the driving face is the gas pressure gradient. Based on the field monitoring data of the hydraulic support in the working face and the single pillar in the mining roadway, the law of mine pressure was obtained. Combined with the monitoring data of the number of drill cuttings and gas in different positions of the mining roadway and the gas concentration change in the upper corner of the working face during mining, the influence of the advanced support pressure and periodic pressure on the gas emission of the coal seam was analyzed. The results show that the advanced support pressure affects the coal seam gas emission by affecting the coal seam permeability coefficient. With the increase in the support pressure, the coal seam permeability coefficient decreases, and the coal seam gas emission decreases. During the period of periodic pressure, the advanced support pressure moves forward, forming a pressure relief zone in front of the working face, which is conducive to the emission of coal seam gas, and periodic pressure provides power for the gas emission.