Numerical Simulation and Aanlysis on Overlying Strata Movement of 3207 Working Face with Large Mining Height in Huoerxinhe Mine

In order to solve the mining problem of the soft thick coal seam with broken roof in Shanxi Huoerxinhe Mine and ensure the smooth and safe mining of 3207 working face with large mining height, numerical simulation was carried out on the influence of the advancing abutment pressure, the delayed stress state and the advance speed of 3207 working face on the coal wall spalling according to the the overlying strata movement rule and the actual conditions of this face and by using FLAC^3D software, the overlying strata movement rule of this face was thus obtained. The research results showed that the peak position of the advancing abutment pressure was about 6 to 7 m away from this face and the peak position of the delayed abutment pressure was 10 to 14 m behind the coal wall of the face; when the advance speed of the face was slower, the damage area caused by the tensile stress and shear stress was larger and the probability of rib spalling increased.