Modelling the poroelastoplastic behaviour of soils subjected to internal erosion by suffusion

Quentin Rousseau (1, 2) , Giulio Sciarra (1) , Rachel Gelet (3) , Didier Marot (1)

1 GeM - Institut de Recherche en Génie Civil et Mécanique
2 ECN - École Centrale de Nantes
3 IEG - Interactions Eau-Geomatériaux

Granular soils subjected to seepage flow may suffer suffusion, i.e. a selective internal erosion. Extending the classical approach of poromechanics, we deduce a new form of the Clausius-Duhem inequality accounting for dissipation due to suffusion and we deduce restrictions on the constitutive laws of the soil. We suggest (i) a possible coupling between the seepage forces and the suffusion kinetics (ii) an extension of an existing elastoplastic model for the skeleton mechanical behaviour. Numerical integrations of the elastoplastic model are carried out under drained axisymmetric triaxial and oedometric conditions. As a result, we prove that the extended model is able to qualitatively reproduce the suffusion induced strains as well as the strength reduction experimentally observed. Predictions on the oedometric behaviour of suffusive soils are also provided.

Mots clés: Suffusion; thermodynamics; poromechanical model

Domaines: Mécanique des solides [physics.class-ph]; Génie civil

Quentin Rousseau, Giulio Sciarra, Rachel Gelet, Didier Marot. Modelling the poroelastoplastic behaviour of soils subjected to internal erosion by suffusion. International Journal for Numerical and Analytical Methods in Geomechanics, 2020, 44 (1), pp.117-136. ⟨10.1002/nag.3014⟩. ⟨hal-02633611v2⟩