Determine the Sensitive Index and Critical Value of Coal and Gas Outburst of Fracturing Coal Mass

In order to determine the sensitivity index and critical value of coal and gas outburst prediction in the fractured area of Xinjing Coal Mine, and determine its applicable conditions, based on the tracking survey data of field outburst prediction index, the paper analyzed and determined the drilling cuttings gas analytic index K₁ and drilling cuttings quantity S as the sensitive indexes by fuzzy mathematics method. On the basis of ensuring the prediction accuracy of outburst up to 65%, the critical value of outburst prediction index was determined by using "three rate method"; the critical value of the drilling cuttings gas analytic index K₁ was 0.4 mL/(g·min^1/2) and the critical value of drilling cuttings quantity S was 6 kg/m; by introducing water content as the applicable condition of critical value of sensitive index, the basic water content of 15 m coal mass within the radial range of fractured borehole was statistically analyzed, and the critical value was determined to be 7.43%.