The effective stress principle: Incremental or finite form?

Different expressions of the effective stress principle can be found in the literature, in particular some are written in finite form and others in incremental form. For the purpose of the paper we take for granted that stress-strain relationships exist or can be obtained for the effective stress coming from both formulations. We investigate the consequences of the choice of particular finite or differential forms when they are introduced in a weak form of the linear momentum balance equation of two- of three-phase porous media for its numerical solution. For partially saturated geomaterials the importance of the capillary pressure-saturation relationship is pointed out.