Study on Key Parameters of Roof Cutting and Pressure Release in Medium-Thickness Coal Seam

Abstract

According to the characteristics of strata behaviors under the condition of roof cutting and pressure release, this paper takes the 5-200 working face of Dianping coal mine as the engineering background, and comprehensively adopts the theoretical analysis, numerical simulation and field measurement to study on key parameters of roof cutting and pressure release in medium-thickness coal seam. The results show that: (1) The theoretical analysis determines that the height of roof cutting is 8.3 m, the angle of roof cutting is 15°, and the distance between the blasting holes is 500 mm; (2) The peak value of stress under the condition of roof cutting is lower 38.8% than it been under the condition of non-cutting, and the maximum displacement of the roof is reduced from 2500 to 420 mm. The first weighting length of main roof on the side of cutting roof is increased by 6 m compared with the non-cutting side, the periodic weighting length is increased by 12 m, the peak stress is reduced by 29.3%, and the average stress is reduced by 20.9%. The size of the roadway is 2601 mm × 4673 mm, which is in line with the numerical simulation results. The roof cutting can significantly reduce stress, deformation, improve the retaining effect on roadway and enhance production efficiency.