Analysis of the impact of close distance coal seam mining on overlying goaf

In order to understand the displacement and stress changes of the roof of the overlying goaf in close range coal seams, takes the 12415 working face of Bulianta Coal mine as the research object.Theoretical calculation and FLAC^3D numerical simulation are respectively used to analyze the calculation of the failure depth of the upper goaf to the floor and the stress distribution of the roof in the lower mining position.The results show that the failure depth of floor in No.11 goaf is 2.93 m.The horizontal range of No.12 coal seam is 10.73 m.FLAC^3D numerical simulation software is used to simulate the mining of the lower 12415 working face through the upper 11401 working face goaf, and the maximum stress concentration coefficient of the roof affected by the upper coal pillar is only 4.1, and the maximum vertical stress is 20.2 MPa.