An Experimental Investigation On The Permeability Of Chemically Grouted Sands And Its Application For Mitigating Underground Sand And Water Inrushes

This paper presents an experimental investigation on the hydraulic conductivity of coarse sand samples before and after chemical grouting. A newly developed device that applies aerostatic pressure is used to prepare the chemically grouted sand, which can also be used to simulate grouting into soil mass at different depths with different pumping pressures. A static high-pressure triaxial test system is then used to investigate the permeability of the chemically grouted sands under a high confining pressure. The experimental results show that chemical grouting obviously reduces the permeability of sand. The results also show that the hydraulic conductivity of the chemically grouted coarse sand increases with increased hydraulic gradients at a constant confining pressure. The hydraulic conductivity of the chemically grouted sand is generally reduced with increased confining pressure. However, under a high confining pressure, the hydraulic conductivity is increased with increases in the confining pressure owing to the rupture of the particles or samples. A case history is then presented, which uses chemical grouting to control groundwater seepage into a deep coalmine shaft and thus demonstrates the feasibility and durability of the use of chemical grouting as a ground treatment to prevent groundwater inrush from sand aquifers.