Study On Mechanism And Prevention And Control Of Rock Burst In Stope Under Irregular Coal Pillar

The paper uses three research methods:theoretical analysis,numerical simulation calculation and field test.With the stope of Y480 area in Tangshan Mine(including three working faces:Y486,Y485 and Y484)as the research background,this paper mainly carries on the research and application to the impact ground pressure mechanism,the impact ground pressure appearance characteristics and the impact ground pressure prevention and control technology based on the engineering dissipative structure.According to a series of problems of the Y480 area of Tangshan Mine,such as:the irregular coal pillars with a large area of 5 coal seams in the upper part of the mining area(with a spacing of 30m),large depth of burial,impact tendency of coal seams,special mining sequence,dense roadway group,and complicated boundary and structure,the stress propagation model of the floor rock stratum is established;the stress propagation law of coal pillar is analyzed;and the influence degree of load concentration on the rockburst pressure is studied;the impact geology model under the action of coal pillar is established;the conditions and mechanism of the impact pressure under the condition are analyzed;and the dissipative mechanism of the engineering dissipator on the impact pressure is analyzed.Based on the distribution characteristics of the stope in the 480 area,the design of the working face recovery sequence is carried out,and the stress distribution characteristics of the stope is analyzed.With the methods of the theoretical analysis and numerical simulation,to study the stress distribution and energy evolution of surrounding rock under irregular coal pillars reveals the characteristics of impact ground pressure of the stope under the upper irregular coal pillar.According to the geological mining conditions in the Y480 region,a sub-regional prevention and control model for the first-class dissipative body and the second-level dissipative structure is established.In terms of the pelvic floor structure presented in the Y480 area,the engineering dissipative structure of the process of preventing and controlling the impact ground pressure and the impact ground pressure based on the engineering dissipative structure are established by adopting the ideas of process control and the methods of impact ground pressure.Based on the above researches,the impact risk of the stope in the Y480 area was evaluated.The first-level dissipative structure was implemented in the lower part of the inverted convex coal pillar in the pelvic floor area,and the second-level dissipative was implemented in the upper part of the inverted convex coal pillar.In the body structure,a number of composite engineering dissipative structures were implemented in the Y484 working face mining process,which realizes the overall prevention and control of the impact pressure of the large scope.