急倾斜薄煤层仰斜开采覆岩应力分布特征研究

摘要

In order to ensure the safety mining in the steep inclined thin seam,base on the deposit conditions and hydrological conditions of the steep inclined seam in South No.2 Mining Block of Longhu Mine,the dispersed element UDEC numerical calculation was applied to study the stress distribution features and failure law of the overburden strata under the condition of the upward mining in the steep inclined seam.The results showed that there were the stress increased zone at the front of the coal mining face and at the solid coal side of the upward mining in the steep inclined thin seam and the stress concentration would be increased in a parabolic and linear individually with the coal mining face pushed forward.The area above the goaf of the coal mining face in the steep inclined thin seam would be a stress reduced area.The connection of the main stress tracing lines could form a stress pressure released arch.The arch height and arch corner of the pressure released arch would be increased with the coal mining face pushing forward.The arch shape would be converted from a symmetrical arch to nonsymmetrical arch to flat arch with the coal mining face pushing forward.The shape of the pressure released arch could reflect the stress transmission relationship between the different strata of the overburden strata and would be closely related to the bedding location of the overburden strata.%为了确保急倾斜薄煤层的安全回采,基于龙湖煤矿南二采区急倾斜煤层的赋存条件和水文工程地质条件,采用离散元UDEC数值计算,研究了急倾斜煤层仰斜开采条件下上覆岩层的应力分布特征和破坏规律。结果表明：急倾斜煤层仰斜开采实体煤侧和工作面前方均存在应力增高区,其应力集中程度随工作面推进呈抛物线和线性增大趋势;急倾斜煤层开采采空区上方为应力降低区,将主应力轨迹线连接形成应力卸压拱,卸压拱拱高和拱角均随工作面推进呈增大趋势,其形状随工作面推进由对称拱—非对称拱—平顶拱转变,卸压拱形态反映出覆岩不同岩层间的应力传递关系,与覆岩的离层位置密切相关。