Mining-induced seismicity of a seam located in rock mass made of thick sandstone layers with very low strength and deformation parameters

In the developed method of forecasting the pressure/stresses in the areas of the rock mass, which are affected by mining exploitation, the formulas linking the results of geophysical measurements of the longitudinal wave anomaly to the pressure values in its impact zone are used. This method was used to locate areas where elevated pressure occurred compared to gravitational pressure, which had a decisive impact on confinement of layers affected by mining exploitation. In such areas the level of confinement/stiffening of the layers is very high, that is why their deformation in the direction of the gobs is limited. In the case of a formation of a large area of gobs, large-size rock blocks are formed in the rock mass, whose mining-induced separation causes their the impact on the ground. Seismic energy accompanying this event is a function of the impact energy reduced by damping resulting from the physiomechanical properties of the cracked substrate.