A series of steady-state vertical infiltration tests were conducted on a 1.0 m highsoil column of Clayey Sand over Fine Sand under various boundary conditions. The testresults show that the pore-water pressures in the Clayey Sand were always negative dueto the existence of the underlying Fine Sand. The pore-water pressures in the ClayeySand increased with the increase in flux or head at the upper boundary and the rise of thewater table at the lower boundary, but the infiltration rate generally decreased followingthe rise of the lower water table. The unsaturated hydraulic conductivity values of theClayey Sand were found to be closer to the predicted drying conductivity curve ratherthan to the wetting conductivity curve. The Clayey Sand was found to be unsaturatedeven when the measured pore-water pressures were either zero or positive suggestingpossible air entrapment in the soil during the downward movement of water.
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