ABSTRACT
The behaviour of an unsaturated porous medium having an elastic solid matrix is studied within the framework of homogenization. The main features of the change of scale method are recalled from a previous paper of the authors. This approach makes it possible to assess the validity of the effective stress hypothesis and, if appropriate, to determine its expression. Special attention is devoted to the influence of surface tension on the macroscopic behaviour. In particular, it is proved that it is not possible to take into account the sorbtion-desorbtion hysteretic phenomena in the framework of an elastic macroscopic behaviour. Moreover, the links between this hysteresis and the inelastic nature of the mechanical behaviour is clarified.
