Gas Drainage Technology of Mining Fracture Developed Zone in High Gassy and Thick Seam

According to the high gas emission from the mining fracture developed zone during the mining process of high gassy and thick seam,the site observation showed the gas in the goaf and the gas in the neighboring seams would be taken over 50% of the total emission gas in the coal mining face and the height of the crack zone in the coal mining face was 15.6828.68 m.Based on the circumstances, based on the traditional gas drainage in the mining seam and the gas drainage from the nei ghboring seam,the high level borehole gas drainage method was applied to the gas drainage in the mining crack development zone. The related parameters of the gas d rainage were determined. The practices showed the high level borehole gas drainage effect in the neighboring seam of the crack zone was higher than the gas drainage in the mining seam and the gas drainage effect of the single neighboring seam and the gas drainage rate of the coal mining face was 53%.