Abstract:Protective layer mining is an effective technical measure to prevent and control rock burst of coal seam groups. In order to explore the relief effect of protective layer under different mining parameters, the influences of mining height, layer spacing and working face length on vertical stress distribution and floor relief degree of protected coal seam were systematically analyzed, and quantified by calculating the relief coefficient. The results show that the increase of mining height and the decrease of layer spacing will lead to the improvement of pressure relief effect. The pressure relief of the protective layer decreases gradually with the increase of the length of the working face, and the pressure relief range increases with the increase of the length of the working face. The analysis of the pressure relief degree of the floor shows that the increase of mining height and working face length is conducive to improving the pressure relief effect of the floor. When the layer spacing is less than 20m, the critical depth of floor pressure relief gradually increases, while when the layer spacing is greater than 20m, the critical depth of floor pressure relief gradually decreases and gradually reaches stability.
