A Soil-Water Characteristic Curve Considering Temperature and Void Ratio under Capillarity and Adsorption

The soil-water characteristic curve (SWCC) is an important constitutive relationship of unsaturated soils. The temperature and void ratio obviously effect the SWCC of soils. Combining the adsorption and capillary water models for soils and introducing a capillary condensation factor, a SWCC model was obtained. Moreover, an analytical solution of wetting coefficient considering temperature was obtained by considering the non-isothermal water-air interfacial tension and enthalpy of immersion per unit area. Then, a temperature-dependent matric suction and SWCC model were established. Additionally, the pore distribution curves at different void ratio can be obtained by shifting and scaling the curve at the reference state. Then, a void ratio-dependent capillary model was proposed. On this basis, a capillary-adsorption decoupling SWCC model considering temperature, void ratio, and capillary condensation was established. The parameters can be determined from two series of test data with different void ratios at same temperature and one data of different temperature. The comparisons between the predictions and measurement indicates that the model is precise in predicting the SWCCs under different conditions.