Mine Strata Pressure Bumping Prevention and Control Technology with Hard Roof Weakening Blast for Fully Mechanized Top Coal Caving Mining Face

In order to prevent the mine strata pressure bumping occurred in the tail gateway of the fully mechanized top coal caving mining face, based on the depo sition and mining technical conditions of the fully mechanized top coal caving mining face in No.11 seam in Xinzhouyao Mine, a pressure releasing blasting technology t 0 weaken the hard roof of the tail gateway was studied and applied.The numerical simulation was applied to analyze and obtain the rational blasting parameters.The res ults showed that when the borehole horizontal projection distance reached 2/3 of the coal pillar width, the borehole could reach the stress concentrated area and the bl asting pressure releasing role would be good.When the space distance between boreholes was 6 m, the blasting cracks would be connected and the blasting effect wou Id be better than the space distance of 8 m.The roof weakening technology could make the stress in coal pillar reduced by 60% and could effectively prevent the mine s trata pressure bumping occurred in the tail gateway of No.8935 fully mechanized top coal caving mining face.