Temperature effect on hydric behaviour for unsaturated deformable soils

Considering an unsaturated soil with pure water, the suction can be expressed with respect to three independent variables: water content, void ratio, and temperature. From the expression of the total differential of the suction, we propose a constitutive relation which links variations of suction, water content, void ratio, and temperature. This relation allows the analysis of several particular cases. At constant temperature, this relation could be represented by a characteristic surface in the parameter space (water content, suction, void ratio). This surface, which reflects the hydro-mechanical couplings in soils, can be considered as a generalization of the classical Soil Water Characteristic Curve (SWCC). At constant suction, the constitutive relation allows to predict the water content variations due to temperature changes. Thus, from a SWCC obtained at a given temperature, the model can predict this curve for other temperatures. This model has been successfully tested by the authors on experiments performed on two different materials.