Abstract:The grouting of mine water prevention curtain generally includes two techniques: surface and underground near ore body curtain grouting, which have been widely applied and achieved good results in water prevention and control engineering of metal and non-metal large water mines. Due to the collapse of a certain iron polymetallic mine caused by goaf, the groundwater in the strong rich water layer of Quaternary gravel and pebble was connected. In addition, the karst development of the underlying crystalline limestone led to the collapse of Quaternary water into the underground through the caving zone and karst filling channel, resulting in a flooding accident. Due to the lack of a relative aquitard on the bottom plate of the ore body and the special spatial distribution pattern of the ore body, it is difficult to use conventional curtain grouting technology. By identifying the spatial distribution characteristics of the water filling channels and relative aquitards in the mining area, and accurately characterizing the hydrogeological model of the mining area, a horizontal grouting curtain is constructed for the limestone karst development area to cut off the hydraulic connection between the Quaternary water and the bedrock aquifer, significantly reducing the water inflow into the mine pit. Based on the distribution pattern and anti-seepage characteristics of the horizontal curtain, a spatial monitoring and early warning system for the anti-seepage effect of the curtain body was set up, which combines fiber optic deformation and water level monitoring, effectively ensuring the water blocking effect of the curtain body and the safe mining of the mine.