The side abutment pressure distribution, the resources recovery, the stability of coal pillar and the mining roadway are considered in determining reasonable width of full-mechanized top-coal caving with large mining height. In order to determine the reasonable width, taking the 8103 mine as the engineering background, firstly, the side abutment pressure distribution of full-mechanized top-coal caving with large mining height is studied by using stress monitoring and theoretical calculation; and 8 m in width of low stress zone, more than 28 m in width of original rock stress zone are determined. Secondly, the width of fractured zone in side coal mass of full-mechanized top-coal caving with large mining height is determined by using engineering analogy and numerical simulation, and about 4 m in width of fractured zone is determined. Finally, the stress, the deformation and fracture and displacement of the gateway excavating and the coal pillars under different widths of coal pillars are simulated by FLAC(3D). The study results show that the coal pillar almost have no bearing capacity and the roadway has large deformation and failure under the influence of mining abutment pressure when the width of segment pillar is 6 m or 8 m; the coal pillar has the stronger bearing capacity and the roadway has small deformation and failure under the influence of mining abutment pressure when the width of segment pillar is 28 m or 30 m. All in all, various elements such as resources recovery, roadway support control, and secondary disaster control are considered comprehensively; and the reasonable width of segment pillar of full-mechanized top-coal caving with large mining height is determined as 28 m.
