Mechanism And Prevention And Control Technology Of Rock Burst In Deep Roadway Area Through Coal Seam Superimposed By Dynamic And Static Load

Aiming at the evolution mechanism and failure mechanism of the deep coal seam roadway area in the process of loading,this paper takes the rock burst of the roadway in the first pan area of Gaojiapu Coal Mine as the engineering background,and takes the surrounding rock structure forms of the roadway under different stiffness types(pure coal,sandstone-coal-sandstone,mudstone-coal-mudstone)as the research object.By means of theoretical analysis,laboratory test,numerical simulation and field analysis and verification,the quasi-static load and the "stress-energy" test of different coal and rock mass under cyclic dynamic disturbance loading are studied.The forces and energies in the deformation and failure process of different coal and rock masses are clarified,and the key locations and release laws of coal and rock mass propagation and accumulation under dynamic and static loads are obtained.Based on the test results,the steady-state index γ of coal is proposed,and the interaction energy model of coal-rock system is established.The measures of energy release and shock reduction for deep roadway through coal seam are put forward to reduce the impact damage degree of roadway caused by dynamic load disturbance and the disaster degree after the occurrence of rock burst.The research results provide some reference for the occurrence mechanism and prevention and control technology of rock burst in deep roadway through coal seam.The main conclusions are summarized as follows:(1)The stress-energy evolution trend of different coal and rock masses under dynamic and static loading is similar to some extent.When cyclic disturbance is applied at a higher stress level,the failure intensity of coal and rock masses is smaller,the time of failure is shorter,and the energy generated is larger.(2)The impact failure process of different coal and rock masses under static and static loading can be divided into the typical stages such as particle ejection,splitting into blocks,block ejection and debris ejection.Among them,the dynamic failure time of "mudstone-coal-mudstone" assemblage is shorter and the impact degree is more severe after being disturbed by dynamic load.(3)The loading process of the coal-rock composite system can be divided into three stages of "absorption-accumulation-release".The maximum principal stress and elastic strain energy of the system change symmetrically with the central axis of the specimen as the symmetry axis.The maximum principal stress and elastic strain energy before the deformation and failure of the coal-rock system are mainly concentrated in the coal body,and the energy is finally released by the coal body.(4)The steady-state index γ of coal is proposed.The possibility and strength of impact failure of coal under the grip of rock mass with different stiffness are related to the value of γ.The smaller the value of γ is,the higher the possibility of impact is and the more severe the impact is.(5)In the deep alley through the coal seam,the measures of drilling pressure relief,energy relief and impact reduction can be adopted to reduce the stress concentration degree of the coal seam and the ability to store elastic strain energy,orderly release the energy of weak rock mass in advance,block the transmission path of dynamic load,and avoid the occurrence of rock burst or reduce the degree of disaster after the occurrence.This paper has 64 figures,8tables and 86 references...