Saturation dilatancy modelling

Biot and Darcy theory shortcomings have been largely overcome by development of a coupled diffusion-dynamic formalism (de la Cruz et al. 1993, Spanos 2001, Spanos et al. 2(X)3). Porosity is treated as an explicit thermodynamic variable, so that dnumerical model development. Nevertheless, if they are solved subject to the assumption of the incompressibility of a liquid saturant, the existence of a slow wave is predicted. It is called the porosity dilation (PD) wave it is not a strain wav, it is a coupled liquid-solid displacement wave, and it has some interesting properties. 

MODELLING OF THE DILATANCY - SATURATION COUPLING DURING EXCAVATION AND CONSOLIDATION OF AN UNDERGROUND STRUCTURE... 

This article describes non-saturated applications of two elastoplastic models respectful of the above specifications with particular attention given to the behaviour at the end of excavation and after a short resaturation process. The influence of dilatancy, softening and damage has been studied on a simplified model. At last an application on a real tunnel is presented. 

In this section, an application of the proposed models is presented. The case studied here is in connection with the future construction of an underground research laboratory for nuclear waste disposal in a claystone formation. The main purpose is to evaluate the desaturation-resaturation process around the excavation during the excavation and the consolidation phases with different rheological laws. Special attention is given to the dilatancy phenomenon that influences the saturation. 

In this article, two improved elastoplastic models taking into account dilatancy and softening, and coupled with the non-saturated approach of Bishop s effective stresses have been successfully tested. The influence of dilatancy on saturation degree and on the short-term stability of a tunnel is shown. The consequences of damage (plastic... 

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