On the modeling of localized failures in saturated porous media through strong discontinuities

This paper considers the modeling of localized failures in saturated poroplastic media through the consideration of strong discontinuities. These discontinuous solutions incorporate a cohesive-frictional law in the poroplastic continuum relating the driving traction and driving fluids free enthalpy (through the consideration of an effective driving traction) with the deformation and uid ow jumps across the surface of discontinuity, including the uid accumulated on it, in the general finite deformation and strain range. This is accomplished through a multi-scale framework with the singular fields associated to the discontinuity eliminated locally in terms of the standard (and regular) large-scale deformation and pore pressure fields, arriving then to a large-scale problem on these quantities that incorporates the localized dissipation associated with the failure mechanisms of interest. This structure translates directly in the formulation of enhanced finite element methods, that incorporate these singular fields without a regularization of the discontinuities. The performance of the proposed models and finite element methods is illustrated with a representative numerical example.