Forecast Of Coal And Gas Outburst When Rock Cross-cut Was Uncovered In Deep Level Of Majiagou Coal Mine

The dynamical phenomenon is occurred in Mjiagou mineral coal seam, approximatelyfifty-four. It is the most severity when rock cross-cut is uncovered.According to the actuality, the predicted gas pressure is as follow: from 1.061MPa to1.65MPa at deep level 9-2 seam and from 0.99722 to 1.5022MPa at deep level 12 seam.Atthe spot, the representative coal samples have been collected, and expansion energy of gas,the hard coefficient and the gas initial velocity have been measured. It concludes that theexpansion energy and the pressure of gas is linear relationship by theories and experiments,then by contrast of the critical expansion energy of gas, the gas outburst critical vale at thedeep level of Majiagou cola mine were 0.63~1.38MPa at deep level 9-2 seam and0.75~1.68MPa at deep level 12 seam. At last, by comparison of the predicted value and thecritical value of gas outburst, it concludes that the gas outburst is potential on the deeplevel in Majiagou coalmine.By the measurement of the hard coefficient and the early speed of the coal sample, thecomprehensive indexes( D, K) of a coal sample was got, and it implies that the result of thegas inflation energy method predicting result is reliable. By the gray theories, it is impliesthe gas inflation energy method is better than the comprehensive index sign method; In theend, two methods, making use of taking out the coal seam gas and the metals framework,are put forward as the prevention measures of the outburst in that mine.The forecast of the outburst is very important for Majiagou coalmine and othercoalmines to exploit coal seam at the deep level.