[en] A thermo-hydro-mechanical model is presented to tackle the complex coupling problems encountered in clay barriers. A detailed formulation. coupling heat, moisture (liquid water and water vapour) and air transfer in a deformable unsaturated soil is given. The formulation of Alonso-Gens' mechanical model for unsaturated soil is also incorporated. Finally, a small-scale wetting-heating test on compacted bentonite is performed for validation; the numerical results are compared to the experimental measurements. (C) 2002 Elsevier Science B.V. All rights reserved.