On the time-dependent behaviour of unsaturated geomaterials

Jean-Michel Pereira (1) , Vincenzo de Gennaro (2, 3)

1 cermes - Géotechnique
2 navier umr 8205 - Laboratoire Navier
3 EPRC-DCS

In this paper a rate dependent model for unsaturated geomaterials is presented. The constitutive laws for the description of the time-dependent behaviour of saturated and partially saturated geomaterials generalize the isotach approach to the elastoplastic strain hardening based constitutive laws for partially saturated soils. The formulation encompasses rate and creep effects together with suction dependency on creep. It constitutes an extension of the work presented in (De Gennaro et al. 2009; Pereira and De Gennaro 2009). Some perspectives about the constitutive modelling of time-dependent behaviour of geomaterials saturated by a single or two fluids, including soft rocks are proposed. Practical applications include modelling of (i) shallow quarries submitted to humidity changes, (ii) oil reservoir formations or (iii) geological storage of CO2. In this study, the formulation of the constitutive model is presented. Numerical predictions including explicit influence of suction on time dependency of material's behaviour are compared to available experimental data on oil reservoir and quarry chalks and discussed.

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Jean-Michel Pereira, Vincenzo de Gennaro. On the time-dependent behaviour of unsaturated geomaterials. Unsaturated Soils - Proc. Fifth Int. Conf. on Unsaturated Soils, Sep 2010, Barcelona, Spain. pp.921-925. ⟨hal-00525903⟩