Geotechnical Engineering Journal of the SEAGS & AGSSEA ISSN 0046-5828
Vol. 50 No. 1 March 2019
Elastoplastic Modelling of Hydro-mechanical Behaviour of Unsaturated Soils
By J.R. Zhang, D.A. Sun and W.J. Sun
ABSTRACT: The development of constitutive models for unsaturated soils is briefly reviewed, and the state-of-the-art of elastoplastic constitutive models for unsaturated soils is summarized. This paper introduces an elastoplastic model that couples hydraulic and mechanical behaviour for unsaturated non-expansive and expansive soils. The two coupled elastoplastic constitutive models are illustrated with laboratory tests to show their application and performance. Hydraulic hysteresis in the soil-water characteristic is modeled as an elastoplastic process with the elastic region of the degree of saturation. The effect of change in degree of saturation on the stress-strain-strength behaviour and the effect of change in void ratio on the soil-water characteristics are taken into consideration in the model in addition to the effect of suction on the hydraulic and mechanical behaviour.
KEYWORDS: Unsaturated soil, Elastoplastic model, Stress-strain relation, Soil-water characteristic, Coupling
