Analysis of reasonable position layout of lower and large thickness coal seam

In the near distance multi coal seam mining,special underground pressure of the lower coal seam appears affected by the mining of upper coal seam.How to arrange the lower seam roadway safely and effectively is not only the key to ensure the safety and efficiency of the mining working face,but also the core of improving the benefits of coal mines.On the basis of the problem of large thickness coal seam mining gateway layout under the coal pillar of upper coal seam in Tashan coal mine,through theoretical analysis,laboratory tests and numerical simulation this paper studies the reasonable layout position of the lower coal seam and draws the following conclusions.Various physical and mechanical parameters of the rock mass of the roadway surrounding rocks are obtained by the mechanical tests providing powerful data support for the theoretical analysis and numerical simulation of the paper;Using the theory analysis and numerical simulation methods,we study the distribution law of the non-uniform stress in the coal and rock mass under residual coal pillar loading;Through the analysis of reasonable layout of the lower coal seam,the layout of the No.3-5 special thick coal seam is determined by the way of inner fault distance 25m.