特厚煤层重复开采覆岩与地表移动变形规律研究

Law of overburden and surface movement and deformation due to mining super thick coal seam

为研究大同矿区特厚煤层重复开采覆岩与地表沉陷问题,以塔山煤矿8103和8104工作面的地质采矿条件为工程背景,沿倾向主断面建立了二维相似材料模型。反演分析了仅开采上覆侏罗系煤层时覆岩沉陷规律、两煤层重复开采时覆岩沉陷规律、离层发育规律、煤柱群垮塌规律以及地表塌陷规律,揭示了该地质采矿条件下覆岩与地表沉陷机理。研究结果表明:采用刀柱式采煤法开采侏罗系煤层,上覆岩层未发生显著的破坏和变形;在特厚煤层重复采动影响下,覆岩以一定的角度向上垮落和裂隙发育,当侏罗系煤层采空区受到下组煤开采扰动时,采空区中煤柱群受扰损伤,支撑能力降低,导致其上覆岩层沉陷加剧,在弯曲下沉带上方形成新的导水裂缝带,覆岩沉陷呈现“四带”发育特征。结合实测数据,分析了工作面沿倾向方向地表移动变形规律,基于Origin 8.0平台和概率积分法进行了二次开发,对倾向观测线上山方向实测下沉数据进行了拟合求参,获取了部分概率积分预测参数。研究结果可对大同矿区开采沉陷治理工程提供参考。

In order to study the problem of overburden and surface subsidence caused by repeated mining in Super thick coal seams in Datong mining area,a two-dimensional similar material model was established based on the actual geological mining conditions of 8103 and 8104 panels of the coal mine.The laws of Overburden subsidence,separation development,pillar collapsed and surface subsidence were analyzed respectively when only overlying Jurassic coal seams and two coal seams were mined repeatedly,and the mechanism of overlying rock and surface subsidence under this Geological mining condition was revealed.Under the influence of repeated mining of Super thick coal seams,overlying rocks collapsed and cracks developed at a certain angle.When the Jurassic coal seam goaf area is disturbed by the lower coal mining group,the coal pillar group in the goaf area is disturbed and the support ability is reduced,resulting in an increase in the subsidence of the overlying rock layer.A new water guide rift zone is formed above the bending zone,and the overlying rock subsidence presents the"four zones"development characteristics.Finally,based on the Origin8.0 and the probabilistic integral method,the paper made a second development,and obtained some probabilistic integral prediction parameters.The research results showed an important guiding significance and reference value for mining subsidence management project in Datong mining area.