Effective Stresses in Multiphasic Porous Media: A thermodynamic investigation of a fully non-linear model with compressible and incompressible constituents

Starting with a short historical review, the present article aims at explaining the effective-stress principle from a general point of view on the basis of the Theory of Porous Media and provides an elaborated example for both unsaturated and saturated soil conditions by consideration of compressible and incompressible solid and pore-fluid materials. Based on this approach, it will be proven that Terzaghi's basic assumption of the effective-stress principle is valid, except for materially compressible porous solids.