顶板砂岩水下煤层开采覆岩导水裂隙带发育高度研究

导水裂隙带发育高度是顶板砂岩水下实施安全采煤的重要技术参数之一。以新集矿区某综采工作面为工程背景，针对工作面回采后采动裂隙导通上覆砂岩含水层易发生突水事故的问题，在分析覆岩岩性特征的基础上，采用经验公式估算、基于关键层位置覆岩导水裂隙带高度预测方法、数值模拟及井下仰孔分段注水法对覆岩导水裂隙带发育高度进行研究。结果表明，基于关键层理论导水裂隙带高度预测方法、FLAC3D数值模拟与井下仰孔分段注水试验结果基本一致，而经验公式预测导水裂隙带发育高度数值较小，存在一定的局限性。工作面回采后，导水裂隙带发育高度最大为57.6 m，裂采比为15.2，且发育形态呈“马鞍型”。 研究结果可为工作面顶板水害治理提供地质依据。

Study on development height of overburden water conducted zone in underwater coal seam mining of roof sandstone

The development height of water conducted zone is one of the important technical parameters for safe coal mining underwater in roof sandstone.Taking a fully-mechanized working face in Xinji mining area as the research object，aiming at the problem of water inrush accident in overlying sandstone aquifer caused by mining deformation and fracture after mining in working face，on the basis of analyzing the lithologic characteristics of overburden，the development height of water conducted zone in overburden was studied by empirical formula estimation，prediction method of overburden water conducted zone height based on the position of key layer，numerical simulation and the underground inverted hole sublevel water injection method.The results show that the height prediction method of water conducted zone based on the key layer theory，FLAC3D numerical simulation are basically consistent with the results of underground inverted hole sublevel water injection test，while the empirical formula predicts the development height of water conducted zone with small values，which has certain limitations.After working face mining，the maximum height of water conducted zone is 57.6 m，the ratio of fracture to mining is 15.2，and the development form belongs to saddle type.The research results can provide geological basis for roof water hazard control of working face.