Study on pressure relief effect in gob-side coal body under the influence of mining

Abstract

By means of multi-field coupling numerical simulation and field measurement, the pressure relief effect and burst elimination range of side coal gas in goaf caused by inclined coal mining are analyzed. Taking the inclined longwall working face of Hongyan Coal Mine as the research object, a fluid-structure coupling model considering elastic-plastic damage was established to simulate the displacement and failure of surrounding rock after mining, and the changes of lateral stress concentration coefficient and permeability in goaf were analyzed. The gas pressure in the range of 10 m to 23 m in the goaf side was monitored and compared with the simulation results. The simulation results show that fracture penetration, stress concentration and initial elastic zone will form on one side of goaf after mining, and the gas pressure in fracture penetration zone can be effectively released. The field monitoring results show that the gas pressure decreases gradually with the advance of working face. It is found that the numerical simulation results are of guiding significance to predict the scope of gas outburst zone, and the elimination range of the inclined longwall working face of Hongyan Coal Mine is determined to be 10 m.

Keywords

• inclined seam
• outburst elimination range
• gas pressure
• numerical simulation
• gob-side coal body