A thermodynamic approach to effective stresses in unsaturated soils incorporating the concept of partial pore deformations

Patrick Dangla (1) , Jean-Michel Pereira (2)

1 Physique des milieux poreux
2 navier umr 8205 - Laboratoire Navier

The thermodynamical analysis presented here follows from the work of Coussy et al., who proposed a thermodynamically consistent model for unsaturated soils that is based on a Bishop-like effective stress to describe the stress–strain relationship while the water saturation (or the capillary pressure) is involved in a saturation-induced hardening in addition to the mechanical hardening. We extended this model to include the effect of interfaces in the mechanical behavior and we showed that the Bishop-like stresses involved in the elastic and plastic responses respectively can take different expressions. The Modified Cam–Clay model used for saturated soils is extended to unsaturated soils through the use of these Bishop-like stresses. This model is compared to some experimental results reported from the literature.

Mots clés: Unsaturated soil; Effective stress; Thermodynamics 21

Domaines: Sciences de l'ingénieur [physics]; Génie civil

Patrick Dangla, Jean-Michel Pereira. A thermodynamic approach to effective stresses in unsaturated soils incorporating the concept of partial pore deformations. Vadose Zone Journal, 2014, pp.2136-2136. ⟨10.2136/vzj2013.06.0110⟩. ⟨hal-01157350⟩