A dependent domain model of capillary hysteresis

A model of capillary hysteresis which takes into account the phenomenon of blockage against air (and water) entry is presented. The model is based on our previous (1974) model II, which predicts any hysteretic path with the aid of two functions, L(ψ) and H(ψ). This model is generalized by adding a new function,р_d(θ)(and ), as has been suggested by D. H. Everett (1967) and G. C. Topp (1971). It is found that is of a lesser significance and can be neglected in most cases. A technique of deriving L(ψ),H(ψ), and from the measured boundary loop and one primary drying scanning curve is presented. A simple method of predicting any hysteretic path is suggested. It is found that the generalized model leads to better results than the models based on independent domain theories for soils having a major portion of their hysteretic loop in the range of air entry value.