The Mechanical Analysis of Dynamic Disturbance and Static Stress under Different Mining Methods

Abstract In order to study the occurrence mechanism of rock-burst accidents under different mining methods, the overburden structural characteristics during long-wall face mining period were studied in detail, and the Elastic Foundation Beam theory was used to analyze the dynamic disturbance and static stress under different mining methods. The results show that, the deflection of the main roof and the composite beam can be calculate and then the energy of them contained; due to the difficult for gangues to support the fractured main roof, the scope of caved overburden is largest and the coal seam share the largest volume of the hanging overburden; the large cutting height mining have the max the concentration coefficient and the thin seam or the top slice mining have the min the concentration coefficient; the structural characteristics of near field key strata largely depend on caving height of the gob, and the deflection and the weighting interval of the main roof changes with variation of mining methods, and then their energy released. Above all, it can be conclude that mining method has large impact on dynamic disturbance induced by the main roof, and further analysis indicate that the structural characteristics of both far field and near field key strata under different mining methods lead to this difference; the mining depth, the proportion coefficient, the tensile strength of the main roof, the main roof’s thickness have large impact on the deflection of the beam and energy released by the main roof and the composite beam, and the elasticity modulus of the main roof, the blank space height in a voussior beam structure have little impact on the deflection and energy released.