Impact Characteristics And Prevention And Control Of Unequal Width Coal Pillar Face In Zhaogezhuang Mine

This paper adopts research methods based on theoretical analysis,mechanical analysis,numerical simulation,and field application.Taking the first mining face of the 14th level in Zhaogezhuang Mine as the research background,the impact of the deep unequal width coal pillar face press The characteristics of impact,appearance of unequal length coal pillars,mechanism of rock burst prevention and control based on weak structures,and prevention and control techniques were studied.By analyzing the mechanical characteristics of the unequal width coal pillars at 4137 West upper working face and the static and dynamic effects of the side pressure on the working face,the impact geostress model of the working face was established and the conditions of deep unequal width coal pillars were revealed.Impact rock pressure mechanism.In the three hard and large structures of coal seams and roofs,the greater the hardness of the rock in the roof and the basement,the greater the instantaneous release of energy from the roof and the bottom of the coal seam in the event of coal seam type impact damage;the impact of the coal seam and the roof and floor in the two hard and soft structural models Under the circumstances,the existence of a weak structure and the non-impact damage can dissipate part of the energy of the system.The non-impact damage of a weak structure on the one hand increases the initial stress of the occurrence of rockburst,and on the other hand reduces the instantaneous release of the rockburst when the rockburst occurs.The energy value;in the top coal mining process,both the top and bottom soft structures in the thick coal seam can gradually release and dissipate energy,thereby eliminating the impact hazard of the coal wall and its nearby troughs during stope mining.The theoretical analysis and numerical simulation methods were used to study the whole process of deformation and failure of coal pillars,and the characteristics of impact pressure behavior of unequal width coal pillar stope were obtained.Under static and dynamic pressure,the stress concentration on the coal pillar and the impact pressure are high,and it has a high correlation with the pillar width.Aiming at the specific conditions of the first mining face,the "L"-shaped weak structure for unequal length coal pillars and the "I"-shaped dissipative structure for the working face are proposed.Impact rock pressure overall prevention and control mechanism.Based on the analysis of impact rock pressure factors,the 4137 Xishang upper working face was evaluated for impact risk,and "L"-shaped weak structure was implemented on the coal pillars and direct roof to make impact energy of unequal length coal pillars effective.Dissipation;An "T"-shaped weak structure was applied to the coal face of the working face and the advance roadway to realize the overall prevention and control of the rock pressure on the working face.