基于工作面顶板疏放水的含水层水力联系研究

Research on Hydraulic Connection of Aquifers Based on Roof Dewatering and Drainage in Working Face

为了弄清蒙陕接壤区深埋煤层某矿井白垩系志丹群与3-1煤层顶板含水层之间的水力联系情况,在首采工作面顶板疏放水过程中,开展了大气降水、含水层水位和水化学变化等方面的研究,结果表明：通过对首采工作面顶板水提前疏放,使切眼附近钻孔涌水量降至3～5m^3/h,水压降至1.0MPa左右,形成了较稳定的降落漏斗.在疏放水过程中,志丹群含水层水位基本保持稳定,3-1煤层顶板含水层水位则下降明显;志丹群与3-1煤层顶板含水层水在矿化度、水化学类型等方面差异明显,且放水过程中水化学特征基本不变,表明志丹群低矿化度水未进入3-1煤层顶板含水层.安定一直罗组地层未发育沟通上下含水层的导水通道,志丹群与3-1煤层顶板含水层之间水力联系较差,为矿井安全生产提供了必要的地质保障.

In order to make clear the hydraulic connection between Cretaceous aquifer and No. 3-1coal seam roof aquifer in a coal mine in the contiguous area of Shaanxi and Inner Mongolia, study was carried out on the atmospheric rainfall, the water level of aquifer and the hydro-chemical variation in the process of roof dewatering and drainage in the first-mining face. The results showed that the advanced roof dewatering in the first-mining made the water inflow near the starting cut drop to 3~5 m3/h and the groundwater pressure reduce to about 1. 0 MPa and finally a stable groundwater depression cone was formed. In the process of dewatering and drainage, the water level of the Cretaceous aquifer basically kept steady, while the water level of No. 3-1coal seam roof aquifer dropped obviously. There were great differences in mineralization degree and hydro-chemical types between Cretaceous aquifer and No. 3-1coal seam roof aquifer, but their hydro-chemical characteristics basically kept steady in the process of dewatering, which indicated that the low mineralized water in Cretaceous aquifer did not infiltrate into No. 3-1coal seam roof aquifer. The Anding-Zhiluo formations didn' t develop water-conducting channels connecting the upper and lower aquifers. The poor hydraulic connection between Cretaceous aquifer and No. 3-1coal seam roof aquifer provided the necessary geological guarantee for safe production of the mine.