ABSTRACT
A new laboratory method was recently developed at the University of Saskatchewan, Saskatoon, for the direct measurement of the unsaturated coefficients of permeability. The method was verified in a testing program involving residual and saprolitic soils from Hong Kong. The method makes use of the pressure plate concept for the direct control of the pore-air and pore-water pressures in the soil specimen. The test procedure is similar to the “inflow equal outflow” method. The coefficients of permeability measured ranged from 10−6 m/s to 10−10 m/s. The choice of porous disks had to have the right relationship between the air entry value and the saturated coefficient of permeability. Experimental results are presented. The experimental results were compared with predicted permeability functions obtained from soil-water characteristic curves along with the saturated coefficients of permeability.
