Mining Pressure Law and Working Resistance of Support in Face with Large Mining Height in Shallow Seam

In order to study the law of ground pressure appearance in the face with large mining height in shallow coal seam and determine its reasonable working resistance of support, the 5-2 coal 503 working face of Daliuta Coal Mine in Shendong is selected as the research object. The law of ground pressure appearance in the face with large mining height in shallow coal seam is studied through the thin plate theory and the field measured ground pressure data, and the support resistance is calculated by combining two different theoretical calculation formulas force analysis. The results show that the initial step distance of 52503 working face is 64.4 m, which is basically consistent with 61.7 m calculated based on thin plate theory; the periodic weighting step fluctuates between 7.65 m and 29.75 m during the normal mining period, with an average of 19.16 m, a dynamic load coefficient of 1.45-1.57, an average of 1.50, which shows a strong mine pressure; during the weighting period, the support resistance along the inclined direction of the working face presents a “convex” type among them, the lower support resistance of the working face is about 69.8% of the middle part, and the upper support resistance of the working face is about 66.5% of the middle part; the working resistance calculated based on the two support strength theories is 17 871 kN and 19 890 kN respectively, which is smaller than the ZY21000/36.5/70D hydraulic support with the rated working resistance of 21 000 kN, which can meet the support requirements of the roof pressure above the working face.