Concurrent Mining During Construction and Water-Filling of a Goaf Groundwater Reservoir in a Coal Mine

Coal mining has aggravated water scarcity in the arid areas of northwestern China. Concurrent aquifer drainage, mining, and water storage is proposed, using a goaf groundwater reservoir (GGWR) to preserve the area’s fragile ecosystem. By continuously draining the overlying aquifer of the working face and simultaneously storing water in the goaf while the working face is mined, this technology can maintain the storage capacity of the GGWR without jeopardizing mine safety. The drainage process was simulated, based on mining conditions of the 11201 working face in the Yuandatan coal mine, to investigate how water pressure variations in the overlying aquifer would affect GGWR construction. Then, two drainage borehole arrangements were simulated. The research demonstrated that the resulting drainage intensity would enable continuous operation of “aquifer drainage-coal mining-water storage”, and that the design satisfies the in-situ drainage and storage requirements. Therefore, concurrent construction and water-filling of the GGWR is feasible.