Three-node zero-thickness hydro-mechanical interface finite element for geotechnical applications

The paper briefly presents the main features of a hydro-mechanical coupled
finite element of interface. The mechanical problems takes into account the the detection
of contact, the development of a contact pressure, the shearing and the relative sliding
between two solids. A three-node discretisation of hydraulic problem allows the representation
of fluid flows across and in the plane of the interface. The method involves a drop of
pressure between each side of the interface and the inner medium. The hydro-mechanical
couplings come from 1) the definition of the total pressure acting on each side of the
interface according to the Terzaghi’s principle; 2) the dependence of the permeability on
the gap variation; 3) the variation of the fluid mass stored within the gap.