Abstract:
In order to study the influence of advanced abutment pressure on mining-induced pressure relief in current seam gas extraction, an experiment research is carried out at 7801 working face in Wuyang Coal Mine. The results shows that, the advanced abutment pressure have a significant influence on mining-induced pressure relief in current seam gas extraction. The gas extraction effect of drilling can be classified into 4 stages according to the distance of gas extraction drilling away from the working face: the initial gas extraction stage, the gas extraction declining stage influenced by advanced abutment pressure, gas extraction increasing stage influenced by advanced abutment pressure and the gas extraction declining stage, among which the later 2 stages are regarded as the effective gas extraction pressure relief stages in current seam. When the arrangement mode of gas extraction drilling is parallel to coal seam dip and open-off cut, the scope of 25.8 m in front of the working face is considered as the effective gas extraction zone and the amount of gas extraction in this zone accounts for 61.75% of the whole gas extraction; when the arrangement mode of gas extraction drilling is parallel to coal seam and inclined to open-off cut, the scope of 44.8 m in front of the working face is considered as the effective gas extraction zone and the amount of gas extraction in this zone accounts for 37.89% of the whole gas extraction.