Coal and gas outburst prediction model based on extension theory and its application

Abstract

To accurately predict the risk of coal and gas outbursts under different conditions, an outburst risk prediction system and risk level indices value system were constructed based on extension theory. The prediction system includes 6 indices and 4 risk levels. The subjective and objective weights of the prediction indices were determined according to a fuzzy analytic hierarchy process and simple correlation function, respectively. Finally, a prediction model for the quantitative characterization of the outburst risk through the degree of correlation of the risk level was established. The outburst risk of 12 high-gas mines was predicted by using the prediction model. The prediction result of the outburst risk level was consistent with actual outburst disaster occurrences, and the variation of the actual outburst coal and rock mass quality was consistent with the degree of correlation of the maximum risk level. Based on typical outbursts of coal seam, the values of gas pressure and coal seam gas content were reduced step by step, and then the adjusted values were substituted into the prediction model. When the coal seam gas pressure was reduced to 0.75 MPa, the outburst risk level was reduced to low risk. This value is consistent with the empirical value (0.74 MPa) that is used to define an outburst of coal seam at a coal mine site. The prediction model has practical significance to prevent coal and gas outbursts, optimize gas drainage outburst prevention technology, and improve process safety risk control in coal mine.