Experimental Study on Floor Damage and Slurry Material Ratio Optimization in Deep and High Confined Water Mining

Deep mining has started in the Huaibei area, and serious threat of high confined water on floor to coal seam is gradually increasing. Based deep project at working face II633 Hengyuan mine, this paper theoretically analyzes damage depth risk inrush from floor. The best proportion grouting materials was quantitatively optimized by indoor experiments, an industrial field test conducted judge effect. results show that failure bottom plate calculated theoretical analysis 31.73 m; a single factor response surface optimization design method determined value each index: cement ratio 0.8, bentonite 2%, reducer 0.6%, sodium silicate 2%. after 18.83~20 m, according monitoring strain method. slurry significantly reduces floor, ensures safe efficient above high–pressure water, reference for under similar geological conditions.