巨厚砂砾岩含水层下特厚煤层保水开采分区及实践

以永陇矿区崔木煤矿为研究背景,分析矿区含(隔)水层与煤层的空间组合及覆岩特征,结合导水裂隙带发育高度探查结果,开展巨厚砂砾岩含水层下特厚煤层保水开采分区及实践研究。结果表明:该区导水裂隙带发育高度为煤层采厚的19.93~23.23倍,已波及上覆白垩系含水层。以所确定的保水开采保护层厚度30 m为阈值,将研究区划分为自然保水开采区、可控保水开采区和保水限采区,并提出各分区相应的保水开采途径。实践表明:巨厚砂砾岩含水层下保水开采的有效途径主要包括控制导水裂隙发育高度,选用适当的工作面布局及推进速度,以及隔水层采动破坏后的恢复与再造。

Division and practice of water-preserved mining in ultra-thick coal seam under ultra thick sandy conglomerate aquifer

Taking Cuimu coal mine in Yonglong mining area as research background,the spatial structure of aquifer (separated) and coal seam and overburden features were analyzed.Then the exploratory results of development height of water-flowing fractured zone was analyzed,and the division and practical research of water-preserved mining in thick coal seam under great thick sandy conglomerate aquifer in the studied area was carried out.It is shown that the water conducting fractured zone height is 19.93-23.23 times to the extraction height,which has spread to the overlying Cretaceous aquifer.The protective layer thickness of water-preserved mining is determined to be 30 m.Thus the studied area is divided into three zones,i.e.nature water conservation mining zone,controllable water conservation mining zone and water conservation limit mining area,and the corresponding water preserving mining methods are proposed aiming at each zone.Practices indicate that the effective ways of water conservation mining under great thick sandy gravel aquifer mainly include controlling the development height of water conducting fractures,choosing the appropriate layout and speed of the working face,and recovering and reconstructing after the destruction of waterproof layer mining.