A research on the influence of geological factors to gas discharge from No.8 un-mined solid coal seam of Baode Coal Mine

Mining is gradually progressed toward the in-depth area of No.8 solid coal seam in No.3 panel of Baode Coal Mine. In order to secure safe mining in this area, a systematic analysis is conducted on the geological factors that influence gas occurrence. Based on the basic data actually measured at site, grey relational analysis (GRA) is adopted for predictive analysis of influencing factors (depth, coal seam thickness, metamorphic grade, sand to mud ratio of roof, sand to mud ratio of floor, geological structure and washout), followed by establishment of a grey relational model. Then, the relation degree among factors is calculated, thus identifying the main controlling factors of gas occurrence. The research result suggests: the main geological factors that influence gas occurrence in No.8 coal seam are geological structure and washout. A model equation is established for prediction of gas content using multiple regression method: y=3.2429+0.0047X1 +0.0079X2 -0.0180X3 +0.0016X4 -0.0215X5 +0.4641X6 +0.2001X7 . This equation demonstrates high degree of fitting.