Ali Alizadeh - PhD Student, Department of Civil Engineering, University of Tehran, Tehran, Iran
Behrouz Gatmiri - PhD Student, Department of Civil Engineering, University of Tehran, Tehran, Iran - Professor, Agence Nationale pour la gestion des Dchets RAdioactifs (ANDRA), France

The aim of this paper is to present a new elastoplastic damage model for unsaturated porous media. The proposed model within the context of poromechanics is intended for constitutive modeling of semi-brittle geomaterials. Independent stress state variables, namely net stress and suction, are adopted as stress variables of the model which are transformed into the damaged state through the definition of effective damaged suction and effective damaged net stress. The model has been implemented in Θ-STOCK Code and predictive capabilities of the model have been evaluated against experimental results from the literature. The proposed model is shown to give satisfactory simulation results which match theexperimental data from a heating test on bentonite samples. The proposed model appears to be robust for modeling of radioactive waste underground repositories.

Unsaturated porous media, coupled thermo hydro-mechanical model (THHM), Damage