Research On Strata Pressure Laws Working Face Lapped Each Other Of The Stagger Arrangement Roadway Layouts In Thick Coal Seams

This paper takes the new technology development project of full-seam mining in thick coal seam, which can solve the 5m seam in typical condition of Xishan coal section and the problems that appeared in top coal caving, as the background. These problems include:the coal on the top of the face end and the mining roadway is not caved out, losing coal and increasing the potential danger of self-ignition; the section coal pillar for protecting the roadway; the gas can't be drawn out easily for the layout of the tailgate along the floor; the difficult in driving and maintain the gateway under the top coal seam; etc. Be combined closely with the theoretical analysis, the analogous simulation experiment, the computer simulation and field application, the paper studies systemic on the strata pressure behavior when using roadway layout of stagger arrangement in thick coal seam. Some results are obtained as follows:(1) By taking the key stratum as the research object, the paper builds the key stratum's elastic-thin-slab mechanics model and being combined with the theory of the broken of beam, takes Strength decision of adjacent key stratums, then get the strength condition between adjacent key stratums from lower layer to upper layer. (2) Based on the theory of elastic thin plate, the boundary conditions of the elastic thin plate before and after the main roof fracture of the first coal mining face and the connection working face are determined. Through the reciprocal theorem, the deflection and bending-moment analytical solution of the main roof are deduced, the conclusion of the main roof moment distribution on the top of the coal wall is reached; (3) The main roof researched on the basis of the elastic thin plate theory, combined with the beam theory, the fracture length is analyzed from the peak spot on the top of the coal wall to the advance direction. Considered the ratio of the geometrical modification of elastic thin plate, the fracture length is determine; (4) The paper has analyzed the Stability Influence of upper key stratum if there is chain Pillar or not between the sections, and gets the stability condition of upper key stratums based on elastic thin plate. (5) Geometric mechanic modal of the key stratum and mined-out area is constituted, and the measure to confirm the height of caving zone is given.