特厚煤层开采覆岩高位离层突水危险性评价

Risk Assessment of Water Inrush from Overburden High-level Bed Separation in Extra Thick Coal Seam Mining

煤矿覆岩离层突水危险性预测评价是制定科学防治水方案的基础和依据。为提高特厚煤层开采覆岩高位离层水害防控的精准性,首先根据离层与开采煤层之间距离及其与导水裂隙带范围的空间关系,判断出特厚煤层开采形成的高位离层位于导水裂隙带顶部附近,并分析了高位离层水涌突的3个基本条件,即相对封闭的可积水离层空间、离层补给水源和下渗的导水裂隙通道;然后在底板突水危险系数法的基础之上,提出了离层突水危险系数的概念,建立了高位离层水涌突危险性评价方法和危险性分级标准;最后采用该评价方法对郭家河煤矿1305工作面顶板离层突水危险性进行了评价,并根据郭家河煤矿和崔木煤矿其他工作面顶板离层突水危险性评价结果对该方法进行了验证。结果表明:郭家河煤矿1305工作面顶板离层突水危险性等级为安全,即不会发生离层突水;郭家河煤矿和崔木煤矿其他工作面顶板离层突水危险性评价结果与实际突水情况基本一致,验证了该评价方法的有效性。该研究成果可为黄陇煤田特厚煤层开采顶板离层水害的精准防控提供理论依据。

The risk prediction and assessment of bed separation water inrush in coal mine overlying strata is the basis for formulating scientific water prevention and control scheme.In order to improve the accuracy of water hazard prevention and control o£overlying strata high-level bed separation in extra thick coal seam mining,firstly,according to the distance between the separation and the mining coal seam and its spatial relationship with water-conducting fractured zone,it is judged that the high-level bed separation formed by the mining of extra thick coal seam is located near the top of water-conducting fracture zone.Three basic conditions of water inrush from high-level bed separation are analyzed,namely>relatively closed water separation space9 separation recharge water source9 and infiltrating water-conducting fracture channel.Then,based on the floor water inrush coefficient method,the concept of bed speration water inrush risk coefficient is proposed,and the risk assessment method and risk classification standard of water inrush from high-level bed separation are established.Finally,this method is used to evaluate the water inrush risk of roof separation in No.1305 working face of Guojiahe coal mine.The results show that the water inrush risk level of roof separation in No.1305 working face is safe,that is,there will be no water inrush from roof separation.The evaluation results of water inrush from roof separation in other working faces of Guojiahe and Cuimu coal mine are basically consistent with the actual water inrush situation,which verifies the effectiveness of the evaluation method.The conclusions can provide a theoretical basis for the accurate prevention and control of roof separation water inrush disaster in extra thick coal seam mining in Huanglong coalfield.