Modelling unsaturated soil behaviour by using degree of capillary saturation and effective inter-particle stress

This paper discusses the role of the degree of capillary saturation in modelling the coupled hydromechanical behaviour of unsaturated soils and proposes a new constitutive model for unsaturated soils by using the degree of capillary saturation and the effective inter-particle stress. In the proposed constitutive model, the shear strength, yield stress and deformation behaviour of unsaturated soils are governed directly by the above two constitutive variables. The model is then validated against a variety of experimental data in the literature, and the results show that a reasonable agreement can be obtained using this new constitutive model