Study On Underground Pressure Control In Fully Mechanized Caving Face Of Burst Coal Seam In Chenjiagou Mine

8512 working face is the first mining face in the Chenjiagou Mine.In the process of excavation,mine pressure appears more strongly,the deformation of roadway surrounding rock is large,and the local protection of the supporting body is destroyed.Based on the geostress test and coal seam burst analysis,the paper reveals the geostress size and coal seam burst tendency.The collapse law of overburden,pressure step and the mechanics characteristics are systematically analyzed by similar simulation and numeral calculations.Propose reasonable prevention and control measures.The burst test shows that the burst energy index of coal seam is 6.73,which is slightly larger than the strong burst judgment.The burst performance of coal sample in saturated water condition is obviously reduced,and the effect of water injection on reducing the burst tendency of coal seam is obvious.Through the similar simulation,it is found that when the working face is pushed to 150m,the main roof is broken and the roof is broken down by 25.5m.When the working face is advanced by 360m,the key stratum is broken and the collapse height is 42m and the collapse angle is about 60°,the periodic weighting length is 26?30 m.Application the numerical analysis,it is found that the high stress concentration appear in the upper corner of the 8512 working face,the maximum vertical stress is 31.2MPa,the stress concentration coefficient is 2.4,and the burst risk is large.The damage of the top coal in the face of the working face is 12?14m,and the surface of the coal face has the shear failure.According to the characteristics of ground stress of 8512 working face in Chenjiagou mine,based on the burst characteristics of coal and rock mass,combined with stress According to the characteristics of ground stress of 8512 working face in Chenjiagou mine,based on the burst characteristics of coal and rock mass,combined with stress concentration,influence range and failure zone,it is proposed to use large diameter drilling pressure relief,roof,coal and bottom plate for deep hole blasting and other relief measures,through the use of abutment pressure monitoring,cuttings and microseismic monitoring,coal rock stress significantly reduced,roadway stability,and achieved good results.