Grouting material and technique in water protection mining above confined water

In terms of the problem of the lowering of water level at Yellow River ecological wetland,which is caused by water inrush into coal working face from the thin aquifuge-low confined water limestone aquifer,this paper used numer- ical simulation,in-situ measurement and mathematical statistics methods to analyze the development rule of the floor failure in mining,and to study the key technology of loess efficient grouting for coal seam floor based on laboratory ex- periments and grouting industrial experience. The results show that the mine water inrush will be reduced more than 90% by grouting de-sanding-decentralized loess slurry under the depth of floor failure,and the high intensity mining caused no further degradation in semi-arid areas. There is a remarkable ecological benefit to ecological wetland.