Analysis on the Regular of Underground Pressure in Large Dip Angle Coal Seam with Soft Roof and Floor

The dip angle of coal seam in Guanyinshan coal mine is between 32 degrees and 39 degrees and the first mining area is X11 and X12. According to the caving degree of the immediate roof in the gob, the intensity of pressure of the main roof is analyzed, and the dynamic load coefficient of the main roof is small. The three-dimensional simulation software FLAC is used to calculate the distance of initial caving and distance of initial pressure of working face. The initial caving distance of the immediate roof at each part of the working face is about 4 m, and the initial pressure distance of main roof is about 20 m on average. This paper analyzes the caving of the main roof: when the distance of initial pressure is 20 m, the caving height of the main roof is about 4 m; when it is pushed to 30 m, the caving height of the main roof is about 10 m; with the continuous mining of the working face, the caving height of the main roof is also increasing, when it is pushed to 90 m, the caving height of the main roof reaches 18 m. Through the analysis of the regular of underground pressure in large dip angle soft roof and floor coal seam mining, it can guide the production.