Study on Distribution of Elastic Energy Under High Hard and Thick Key Strata Mining

Under the mining of high hard and thick key strata, the elastic properties are abnormal. The numerical simulation method is used to study the distribution characteristics of elastic properties under the condition of hard and thick layer. The study shows that the hard and thick strata of working face in the process of mining, in front of the coal wall and the bottom of the hard and thick strata of coal and rock in front of the coal wall is in the state of high energy, which is prone to high energy micro-seismic events; in thick and hard rock breaking process, large amounts of energy is released caused by coal rock mass energy increasing suddenly in the dynamic disturbance caused by coal rock under the action of strong vibration, which easily induced mine earthquake, rock burst, pressing frame, coal and gas outburst and water separation and other major disasters. With the increase of the thickness of the hard and thick strata, the energy concentration in front of the coal wall before and after the breaken is decreased gradually, and the energy concentration range of coal and rock mass at the bottom of the hard coal seam is increased. The results of this study can be used for the prediction and prevention of dynamic disasters in the mining of high hard and thick strata.