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

The paper presents the main features of a hydro-mechanical coupled finite element of interface. The mechanical problem accounts for the detection of contact, the development of contact pressure, shearing and relative sliding between two solids. A three-node discretisation of hydraulic problem allows the representation of fluid flow 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. Hydro-mechanical couplings result 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 permeability on the gap opening; 3) the variation of the fluid mass stored within the gap.