Study on optimization and evaluation of continuous mining scheme in coal seam group

In order to optimize the continuous mining scheme of coal seam group in Yushuling Coal Mine, FLAC3D simulation is used to study the coal seam integrity and working face stress distribution law under two continuous mining schemes of downward mining and upward mining of coal seam group, and the economic benefits of the two schemes are compared. The results show that the coal seam suffers plastic damage to a certain extent during upward mining, but the damage scope of the coal seam plastic zone can be effectively reduced by arranging the transportation roadway and return air roadway of the lower No.7 and No.8 coal seams and the transportation roadway and return air roadway of the lower No.10 coal seam in an inboard way of 10 m. The undamaged areas of the lower No.7 and No.8 coal seams account for 87.5% and 60.4% respectively, and the integrity of the coal seam meets the requirements of safe mining. Compared with the downward mining, the average stress of the lower No.7 and No.8 coal seams during upward mining is