DIFFUSE BIFURCATIONS OF POROUS MEDIA UNDER PARTIALLY DRAINED CONDITIONS

This paper presents a procedure which utilizes an energy functional of the apparent solid skeleton (solid skeleton + fluid/solid interface) and higher- order mixed-field finite element to assess the stability of porous media under partially drained conditions. Assuming that the porous medium is fully saturated and the solid skeleton deformation is infinitesimal, we show that the static equilibrium and the sufficient conditions for the onset of diffuse bifurcations can both be derived from the same energy functional in an incremental fashion. A three-dimensional example is included to demonstrate the predictive capacity of the proposed procedure.