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The study on the subsidence of backfill mining block has been a concern of many scholars. A mechanical model of plate subsidence is established by studying the roof of a filling mining area in Luo Iron Mine in this paper. The boundary conditions are given, and the Navier method is used to solve the problem. Based on the thin plate model, the subsidence distribution map of the roof of the underground plate area is obtained. Based on the basic calculation parameters, the influence of a different foundation coefficient, mining depth, length-width ratio of plate area, elastic modulus of roof rock, and thickness of roof on the subsidence of roof is studied. According to the deflection calculation formula obtained, the expression of the internal force and stress is deduced, and the distribution of stress and shear stress on the upper and lower surfaces of the roof is analyzed. The dangerous area of the roof can be obtained, which provides a theoretical basis for the daily maintenance of mine safety.

When blasting to enhance permeability in deep-buried soft coal mining face with a hard roof whose gas drainage requirement is higher, the charging hole and control hole (which doubles as drainage hole) are easy to be deformed and damaged, seriously affecting the blasting implementation and effect. Combining with the stratum characteristics of soft coal seam and hard surrounding rock, the idea of arranging boreholes near the surrounding rock to reduce deformation, inspired by the end effect, is put forward. Then, the experimental research on the deformation characteristics of boreholes at different distances from the surrounding rock is carried out, and the results show that the closer the borehole is to the roof (floor), the smaller the deformation, under the same stress conditions and within a certain distance. Based on this, a new scheme of arranging control holes and blasting holes near the roof and floor is proposed and designed. The field test results show that the blasting of 60 m deep holes are successfully realized and the remarkable permeability enhancement effect is achieved, verifying the feasibility and effectiveness of the improved scheme. This study explores a new blasting permeability enhancement scheme with practical value and reference significance for deep-buried soft coal mining face with a hard roof.