Regression analysis of major parameters affecting the intensity of coal and gas outbursts in laboratory

Estimating the intensity of outbursts of coal and gas is important as the intensity and frequency of outbursts of coal and gas tend to increase in deep mining. Fully understanding the major factors contributing to coal and gas outbursts is significant in the evaluation of the intensity of the outburst. In this paper, we discuss the correlation between these major factors and the intensity of the outburst using Analysis of Variance (ANOVA) and Contingency Table Analysis (CTA). Regression analysis is used to evaluate the impact of these major factors on the intensity of outbursts based on physical experiments. Based on the evaluation, two simple models in terms of multiple linear and nonlinear regression were constructed for the prediction of the intensity of the outburst. The results show that the gas pressure and initial moisture in the coal mass could be the most significant factors compared to the weakest factor - porosity. The P values from Fisher's exact test in CTA are: moisture (0.019), geostress (0.290), porosity (0.650), and gas pressure (0.031). P values from ANOVA are moisture (0.094), geostress (0.077), porosity (0.420), and gas pressure (0.051). Furthermore, the multiple nonlinear regression model (RMSE: 3.870) is more accurate than the linear regression model (RMSE: 4.091).