Research on the coal pillar width of gob-side entry driving in fully mechanized caving face in extra thick coal seam
To investigate the influence of coal pillar width of gob-side entry driving in fully mechanized caving face in extra thick coal seam on the surrounding rock deformation,roadway squeezing deformation,and coal wall spalling,Taking the return airway of 8202 fully mechanized caving face in Jinneng Holding Coal Group Tongxin Coal Mine Shanxi Co.,Ltd.as research background,based on the practical geological conditions,reasonable coal pillar width was calculated by limit equilibrium theory formula.A three-dimensional computational model was constructed by using FLAC3D 6.0 numerical simulation software to simulate coal seam excavation and the variation in vertical stress distribution and displacement field with different coal pillar widths in gob-side entry retaining,which achieved the optimal coal pillar width of 10 m.Similar simulation experiments validated that the roadway roof sank by about 261 mm with a coal pillar width of 10 m,when the deformation of the coal pillar was about 211 mm.The deformations were within the allowable range,verifying the rationality of the 10 m coal pillar width.