Abstract:
In order to investigate the overburden displacement and pressure relief effect of near-distance coal seam group, the PHASE 2D finite element software was used to develop a numerical model for single protective layer with a consideration of the goaf compaction.The overburden stress evolution ahead and behind the working face, the development of plastic zone of coal wall, and the displacement of surrounding rocks in the face area and overburden were obtained.The results show that: The support pressure coefficient grew first and then stabilized in the goaf.The largest abutment pressure coefficient of 1.73 occurred at 4 m ahead of the face.The recover pressure in the gob area was not restored due to the pressure relief of the protective layer mining.The width of plastic zone of working face at the main coal seam increased first and then stabilized with the maximum width of 2.50 m.The roof in the face area squeezed the coal wall, which showed a tendency of movement to the gob direction.The maximum displacement of the coal wall was 0.24 m at the top position.The overburden displacement was symmetrical.The maximum displacement of the roof were 0.90 and 0.40 m for the protective layer and the main coal seam, respectively.