大采高综放面区段煤柱合理留设研究

侧向支承压力分布、资源回收率以及煤柱和巷道的稳定性是大采高综放面区段煤柱宽度留设要兼顾的因素，为了确定大采高综放面区段煤柱宽度，以某矿8103面为工程背景，首先，采用理论计算和现场应力监测等方法确定大采高综放工作面倾向支承压力分布规律，得出应力降低区宽度约为8 m，原岩应力区为巷帮侧28 m外。其次，采用工程类比方法确定大采高综放工作面巷帮外侧煤体严重破裂区宽度约为4 m。最后，采用FLAC3D数值软件分析了下区段工作面回采时窄煤柱（6、8 m）和宽煤柱（28、30 m）的应力场、位移场及塑性区特征，获得不同煤柱宽度时巷道和煤柱力学特征。研究表明：当煤柱宽度6 m和8 m时，在采动支承压力下煤柱几乎无承载能力，且巷道变形量较大；当煤柱宽度28 m和30 m时，在采动支承压力下煤柱中央仍有一定的弹性核，煤柱保持稳定且巷道变形量较小。综合考虑资源回收、巷道稳定性、次生灾害控制等因素，确定大采高综放工作面区段煤柱宽度为28 m。

Study of reasonable width of full-mechanized top-coal caving with large mining height

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 FLAC3D. 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.