From mixture theory to biot’s approach for porous medi

Two apparently di}erent approaches are used in dealing with the mechanics of a deform! able porous medium ] mixture theories on the one hand\ and purely macroscale theories\ which are mainly associated with the work of Biot\ on the other hand[ In the mixture theories\ the porous medium is represented by spatially superposed interacting media\ while macroscale theories assume that standard concepts of continuum mechanics are still relevant at the macro!level[ The aim of this paper is two!fold[ First\ it is shown that the macroscale _eld equations derived from mixture theories can be reformulated in terms of the measurable quantities involved in the macroscale theories[ Second\ it is demonstrated how these _eld equations\ including the fundamental inequality obtained from the second law\ entail the existence of a macroscale C!potential upon which a thermo! dynamically consistent formulation of the constitutive equations can be _rmly founded[ 0887 Elsevier Science Ltd[ All rights reserved[