Capillary hysteresis internal variable model of unsaturated soils

Soil-water characteristic curve describes the relationship between suction and volumetric water content of unsaturated soils. Air-entry has great influence on the drying scanning curves while the starting points of the scanning curve were at the highly saturated range. Based on capillary hysteresis internal variable model and conventional soil-water characteristics theory of unsaturated soils, a modified model which can simulate soil-water characteristic relationship that could consider the influence of air-entry is proposed. The influence of the air-entry on the drying scanning curves while the starting points were at the highly saturated range could be considered while this model is used. Numerical calculations are carried out on several kinds of soils. The simulating results show that the modified model is able to simulate the drying scanning curves while the starting points of the scanning curve were at the highly saturated range better than the capillary hysteresis internal variable model does.