Study on water filling path in the Jiepailing mining area of Hunan Province

In the Jiepailing mining area, during the exploration and mining of deep polymetallic ores, the water filling in the pits and extensive karst ground collapses in the Yujia area occurred.Although previous studies have investigated the hydrogeological conditions in the mining area, the potential sources and pathways of water filling that threaten mine safety and damage the surrounding geological environment, are not clear. This study investigated the hydrogeological conditions and analyzed the pathways of water filling in the Jiepailing mining area by using systematical analysis of hydrogeological data from various stages,ground surface investigation, geophysical exploration, drilling, and pumping tests. The results show that: (1) the northeastern fault F303 is found,loocated in the southwestern part of the study area. (2) In the western part of the mining area the absence of the aquifuge between F201 and F32 leads to Shidengzi Formation directly contacting the Hutian Group and Zimenqiao Formation.It constitutes the main pathway of water filling in the mine pits, affected by F201, F303, and F32. In the northwestern part of the mining area, the contact zone between the granodiorite porphyry and the surrounding rock has good water-richness, forming the other pathway for water filling in the mine pits. The main sources of water filling are the groundwater in the western Hutian Group and Tianweixi river water. This study suggests executing curtain grouting on the west side of F1 by the lower impermeable layer group to block water pathways within the Hutian Group of the Zimenqiao Formation, thereby interrupting the hydraulic connection between the mining area and the river water, as well as groundwater in the Hutian Group. The results can provide basic information for the implementation of water prevention and control in the mine area.