采动覆岩冒裂安全性分级分区预测研究

Study on safety classification and zoning prediction of mining overburden fracture and caving

针对顶板破碎冒落、导水裂隙带及含水层裂隙发育等问题,基于经验公式分析确定煤层开采"两带"发育高度,通过采用有限元数值计算软件FLAC3D分析采动裂隙发育程度,在重力作用下,覆岩运移规律由采空区中心向四周均匀发展,覆岩均匀移动引起拉伸应力区由中心向四周发展并呈U型分布。结果表明,导水裂隙带发育高度和4#煤层至洛河组岩层高度差是判断导水裂隙带是否沟通洛河组含水层的标准。针对煤层顶板洛河组冒裂安全性划分为危险强区、危险中区、危险弱区及安全区。

Aiming at the problems of roof breakage and caving,water conduction fracture zone and aquifer fracture development,the development heights of"two zones"during coal seam mining were determined based on empirical formula analysis.The development degree of mining fracture was analyzed by using finite element numerical calculation software FLAC 3D,because of gravity,the movement deformation of overburden rock was uniform from the center of goaf to the both sides,and with the development of rock movement,the tensile stress area showed U-type distribution and developed from center to both sides.The results showed that the height of the water-conducting fracture zone and the height difference between No.4 coal seam and Luohe formation stratum were the judge standard of whether the water-conducting fracture zone connected Luohe formation aquifer or not.The roof of No.4 coal seam could be divided into three zones:high fracture and caving risk zone,medium fracture and caving risk zone,low fracture and caving risk zone and safety zone.