Determination of sensitive index for prediction of coal outburst risk in Chiyu Coal Mine

Taking No.2 coal seam of Chiyu Coal Mine as the research object, the grey correlation analysis method was used to predict the drilling cuttings quantity S and gas desorption index of drilling cuttings Δh₂ (the "two indicators") and to determine the sensitivity between the "two index" and the possibility of outburst of No.2 coal seam; combined with "three rate method"(predicted outburst rate, predicted outburst accuracy rate, predicted non-outburst accuracy rate), the prediction index of outburst risk was analyzed and the critical value was determined; the "three rate method" was used to analyze the "two indicators" and verify the validity of the critical value. The results show that: grey correlation degree P(S)=0.909>P(Δh₂)=0.896, the S is more sensitive as a predictor; the critical values of S and Δh₂ are determined to be 7.4 kg/m and 200 Pa, respectively. The field effect test shows that the critical value of the prediction index of No.2 coal seam outburst risk is reasonable