COMPARISON OF WATER CONTENT-PRESSURE HEAD DATA OBTAINED BY EQUILIBRIUM STEADY-STATE AND UNSTEADY-STATE METHODS

The water content-pressure head relationship for a small, well-confined, rectangular sample of fine sand was obtained under different water flow conditions. Water contents were measured by a gamma system and press ure heads were measured by a tensiometer-pressure transducer combination. During drying, more water was retained in the sand at a given pressure head in the unsteady flow case than in the static equilibrium and steady-state cases, which agreed with each other.