49 / 2023-05-15 20:29:44

Energy characteristics and on-site prevention and control of coal rock burst failure induced by dynamic load disturbance in deep roadway

Dynamic load disturbance; deep roadway; deformation energy; body deformation energy; plastic zone; microseismic; rock burst

The surrounding rock of deep roadway is in the state of limit stress equilibrium. Under the environment of high vertical stress and strong tectonic stress, the dynamic load disturbance is prone to impact damage, which seriously hinders the safe and efficient production of the mine. In view of the frequent occurrence of rock burst in the main roadway of the first panel of Gaojiapu Coal Mine, based on the analysis of the energy characteristics of microseismic monitoring of rock burst failure in deep roadway, the energy characteristics of rock burst failure in deep roadway are studied by theoretical analysis and numerical simulation. The results show that when there is no impact danger in the roadway, the total energy of the microseismic day continues to remain at an energy level of ≤ 10³ J, which is in a state of stable energy release. When the weak impact is dangerous, the total energy of microseismic day is 10⁴ J ; in the case of moderate impact risk, the total energy of a microseismic day during one month is 10⁵ J ; strong impact danger : the total energy of two or more microseismic days during a month is 10⁵ J, and the energy fluctuates greatly. At the initial stage of dynamic load disturbance, the plastic zone of roadway surrounding rock roof expands rapidly. In the middle and late stages of dynamic load disturbance, the plastic zone of roadway surrounding rock gradually develops to the floor, which will cause floor heave under the influence of bottom coal. The expansion of plastic zone consumes the deformation energy stored in coal and rock mass. If the dynamic failure occurs in coal and rock mass, the volumetric strain energy stored in coal and rock mass will be converted into kinetic energy, forming roadway rockburst. On the basis of numerical simulation results and theoretical analysis, the optimal angle of large diameter borehole construction in a panel roadway is proposed. After on-site microseismic and drilling cuttings test, the pressure relief effect is good.