Dynamic Load Triggered High Static Load Development Roadway Force-energy Response Characteristics And Instability Impact Mechanism

In deep mining,the surrounding rock is in a state of high static load,and the small dynamic load stress increment caused by mine earthquake can make the superimposed load exceed the critical value and induce coal rock impact failure.The stress of coal and rock mass is in the first-order relationship with depth,and the energy is in the second-order relationship with depth.Energy is very important to study the mechanism of rock burst in kilometer deep wells.In view of this problem,many scholars have mostly studied the energy qualitatively in the macro sense,and there is a lack of research on the energy types that cause the static failure of coal and rock mass and the impact of coal and rock mass.Taking the main roadway in the No.1 mining area of Gaojiapu coal mine as the engineering background,this paper makes a semi quantitative study on the energy in the process of impact failure of roadway surrounding rock,studies the temporal and spatial evolution law of surrounding rock vibration field of deep roadway under mining disturbance by using on-site mine vibration monitoring,and simulates and analyzes the temporal and spatial evolution law of eccentric stress field,distortion energy field and failure field of roadway surrounding rock under dynamic load disturbance through numerical simulation,based on theoretical analysis,the "force-energy criterion" for instability failure of surrounding rock in deep roadway and the "energy criterion" for impact failure are established,the impact failure mechanism of surrounding rock in deep roadway is revealed.In view of the simulation research results,a multi-dimensional pressure relief prevention and control system is proposed,after the on-site practice of the main roadway in the No.1 mining area of Gaojiapu coal mine and the monitoring and inspection of mine earthquake,the pressure relief effect is good and the stress and energy concentration of the roadway are effectively prevented.The research results can provide a certain theoretical basis and reference for the prevention of rock burst in coal mine roadway under similar conditions,as well as the active regulation of disaster pregnant environment,disaster reduction and prevention and control.The main conclusions are summarized as follows:(1)According to the induction and analysis of field monitoring data,the mine earthquake energy threshold and high-energy mine earthquake frequency threshold of different levels of impact risk of main roadway in the No.1 mining area of Gaojiapu coal mine are put forward.(2)Under the action of dynamic load disturbance,the deviatoric stress and distortion can be concentrated in the shallow part in the early stage of the two sides of the roadway.The distortion can fully accumulate in the original plastic area.When the "force energy criterion" is met in the process of transferring from the shallow surrounding rock to the deep part of the roadway,the original plastic area expands rapidly and forms a new plastic area.(3)Residual energy in coal and rock mass when ΔU = 0,the coal and rock mass is subject to approximate static failure,and the residual energy ΔU > 0,the dynamic failure of rock mass occurs,residual energy without considering energy loss ΔU is mainly volume strain energy,accounting for about 1/2 of the total elastic strain energy.(4)The practical scheme of multi-dimensional pressure relief measures combining large-diameter drilling pressure relief and coal blasting pressure relief is put forward.After the mine earthquake monitoring and inspection,the multi-dimensional pressure relief measures have good pressure relief effect.This paper has 54 figures,8 tables and 83 references.