Abstract
Water retention curve is one of the most important properties of soil. In previous works, its range less than or equal to pF3 has been mainly focused due to significance of phenomena in wet condition and short of experiment data at high suction. In this research, extrapolation of water retention curve in high suction range is examined using particle size distribution of a soil. Soil moisture covered with mono molecular film of H2O is estimated accurately from specific surface of a soil which is obtained from the particle size distribution, and coincides with experiment data. van Genuchten's formula in wet condition and Brooks and Corey's one in dry condition are applied in order to extrapolate water retention curve. Five types of soil are employed to validate the proposed method and it shows that extrapolated curves have good agreement with the experiment data. It is possible physically to extrapolate the curve in high suction range without experiment data by means of the proposed method.
