Research On The Distance Of The Same Coal Seam And The Layout Of The Roadway In The Dadijing Coal Mine

In this paper,combined with the occurrence conditions of the near-distance 5-1 coal and 5-2 coal mining seams in the Dadijing coal mine,through the combination of theoretical analysis and numerical simulation,the failure characteristics of the mining floor and the stress distribution of the floor rock in the upper coal seam are studied.The upper and lower working faces were studied with the wrong distance and the layout of the mining roadway in the lower coal seam,and the following results were obtained:(1)By using the slip line field theory to analyze the damage characteristics of the upper 5-1 coal after mining,and the geological conditions of the coal seam of the Dajingjing coal mine,the maximum damage depth to the bottom plate after the upper coal seam mining is 9.35m.(2)Using the stress distribution formula of the bottom plate derived from soil mechanics,the stress distribution curve on the floor rock and the vertical transfer of the bottom plate corresponding to the lower distances corresponding to the coal pillars with different widths under different uniform widths are calculated under uniform load.(3)Under the two kinds of error distance theory of the voltage regulation zone and the decompression zone,the wrong range of the same coal seam is obtained.After comparing the thickness of the coal seam interlayer and the integrity of the coal roof,the mine is determined to adopt the decompression zone.The minimum offset is 16.75?29.85m.The vertical stress and influence range of surrounding rock during the same mining period of the two coal seams were analyzed by FLAC3D numerical simulation.The simulation verified the rationality of the theoretical calculation of the fault distance in the decompression zone.(4)Through theoretical calculation and numerical simulation,the influence range of the coal pillar support pressure and the damage characteristics of the bottom plate in the upper coal seam section are analyzed,and the layout of the lower 5-2 coal seam mining roadway is guided.The coal pillar width of 5-1 coal section does not meet the requirements of external faulty roadway layout.The numerical simulation is used to analyze the superposition of the stress field of the upper section coal pillar and the lower coal seam roadway under the overlapping roadway layout.The overlapping arrangement is not feasible,and it is determined that 5-In the wrong layout of the 2 coal mining roadway,the numerical simulation analysis shows that the internal error distance is 6m.(5)Through the above research on the short-distance coal seam with the same mining distance and roadway position,supplemented by engineering examples,the conclusions of the close-distance coal seams with the same mining distance and roadway layout are correct.