INFLUENCE OF FREEZING TEMPERATURE ON HYDRAULIC CONDUCTIVITY OF SILTY CLAY

Hydraulic conductivity of thawed consolidated slurries of a silty clay from Lachute, Quebec, Canada, subjected to closed-system freezing at different temperatures ranging from -2 to -12 degrees C were determined from constant-head permeability tests. The permeability index defined as the slope of the relation between log k and void ratio was found to increase with decreasing temperature. It was also established that the ultimate permeability index was related to the temperature at which no further change in unfrozen water content occurs. For the silty clay studied, the permeability index increased from 1.4 for the unfrozen soil prior to freezing to a maximum value of 8 at a temperature of -12 degrees C.