急倾斜特厚煤层顶板非对称平顶型拱结构对比分析

摘要

Great differences have existed between both the occurrence and force condition of roof structure in steeply inclined and extra thick coal seam and gently inclined coal seam after their excavation,which result in various structures being formed when the roof losing stabilization under the two circumstances.This paper employs comprehensive methods such as theoretical analysis,numerical simulation and field data comparison,et al,aiming at the stability of supports employed in steeply inclined and extra thick coal seams of Urumqi mine region,revealing the dynamical evolution of the asymmetrical flattopped arch structure in the roof of steeply inclined and extra thick coal seam.The research results show that flat-topped arch structure could be formed after collapse of the roof of steeply inclined thick coal seams,and parameters such as arch height,length and crown keep declining with the increase of coal seam angle.The position of arch crown moves towards the shallow surface,roof falling range and caving rock mass decrease,and bearing load of the support reduces.%急倾斜特厚煤层(倾角大于45°)水平分段综放开采与缓倾斜煤层综放开采后的悬空顶板在赋存状态和受力环境上均存在明显差异,导致2种情况下顶板失稳垮落后所形成的顶板结构区别较大.以乌鲁木齐矿区急倾斜特厚煤层顶板结构演化规律为研究目标,采用理论分析、数值计算和现场监测等综合方法,揭示急倾斜特厚煤层非对称平顶型拱结构随煤岩层赋存角度变化的演化规律.结果表明:急倾斜特厚煤层顶板垮落后能够形成平顶型拱结构,并且随煤层倾角增大,非对称平顶型拱结构的拱高、高跨比和半拱跨度比均减小,拱顶位置向地表浅部方向移动,顶板垮落范围和垮落岩体的体积减小,支架承受载荷降低.