中国矿山工程

The sources of water inrush were analyzed using the tunnel water inflow prediction method and C14 tracing technique. Based on the Q-value assessment of the surrounding rock mass and unsupported span analysis, three initial mining method schemes were selected: pre-cut top medium-deep hole room-and-pillar subsequent filling, mechanized upward horizontal stratified filling, and mechanized upward drift filling. The disturbance ranges of each mining method were analyzed through FLAC3D numerical simulations. Ultimately, the mining method was recommended through a comprehensive comparison of the technical, economic, and safety aspects of the schemes. The results indicate that the primary source of water inrush in the deposit is the karst confined aquifer in the floor, with a maximum water inrush rate reaching 35000m3/d. The disturbance range of mechanized up-approach filling method is the smallest, and the disturbance range is 3~4m. Considering the current grouting reinforcement range of 15 meters, the thickness requirements for the safety isolation layer in the aquatic environment, and the technical and economic indicators of the schemes, the mechanized upward drift filling method was preferentially recommended. Field industrial tests demonstrated that implementing multi-sequence advanced grouting reinforcement in the mining area significantly reduced the water inrush in the stope. The stope achieved a comprehensive mining capacity of 110t/d, with a loss rate of 6% and a dilution rate of 4%. This study provides technical support for the safe and efficient mining of gently inclined orebodies in water-rich environments.