Abstract: In order to determine the reasonable staggered distance and roadway layout of the close coal seam and the same working face in Dadijing Coal Mine ,the failure characteristics of the upper coal seam to the lower floor after mining are analyzed by using the slip line field theory.Combined with the geological conditions of the coal seam of the mine,the maximum failure depth of the upper coal seam to the floor after mining is 9.35 m.Based on the two kinds of stagger distance theories of pressure stabilizing area and pressure reducing area,the range of staggered distance of the same mining coal seam is obtained.After comparing the factors such as the thickness of the interlayer of the short-distance coal seam and the integrity of the lower coal roof,it is determined that the theory of mining in the pressure reducing area is more reasonable,the minimum stagger distance is 16.75～29.85 m.Through the numerical simulation analysis,the superposition of the stress field of the lower and upper coal pillars and the lower coal seam roadway is found,and the internal staggered layout of the 5-2 coal mining roadway is determined,the internal staggered distance is 6 m.Through theoretical numerical calculation and numerical simulation analysis,the reasonable staggered distance and roadway layout of the same mining face are obtained to guide the production of the mine.

Key words: Close coal seam, Reasonable staggered distance,Roadway layout, Floor failure feature, Theoretical calculation, Numerical simulation