Study on the Water Source for Filling the Weak Rich (Conductive) Water Aquifer in the Changxing Formation Limestone of Coal Seam Roof

With the increase of mining range from shallow coal seam outcrops to deep With the increase of mining range from shallow coal seam outcrops to deep mining and the improvement of mining intensity in the mining area, there has been a phenomenon of no water inrush in shallow coal mines and abnormal water inrush in deep coal mines in karst landform areas of Guizhou.The project conducted a study on the water source of water inrush in the Xinhua mining area of Jinsha County, Guizhou Province. The research results indicate that the overlying Changxing Formation limestone of the Longtan Formation is a weak (conductive) aquifer, and there is no possibility of water inrush in normal stratigraphic blocks. The spatiotemporal distribution characteristics of the water inrush working face have verified that the Changxing Formation limestone in the shallow mined area has been damaged by mining activities, resulting in a large number of cracks in the rock mass and the formation of a large-scale water accumulation area, becoming a water source for the water inrush in the working face below and a fast supply channel for atmospheric precipitation. The analysis of surface water and mine water quality data shows that the water quality types of mine water and surface water are basically the same, and they are HCO3•SO4-Na type water. The correlation curve between mine water inflow and atmospheric precipitation verifies that the cycle of atmospheric precipitation supplying the mine in Jinyuan Coal Mine is about 10 months before pit closure, and 1 month after pit closure; The Changxing Formation limestone serves as a water-conducting channel, and atmospheric precipitation serves as a source of replenishment for mine water. The research results provide scientific basis for the treatment of atmospheric precipitation water damage in sudden water inrush mines (areas) under similar hydrogeological conditions.