Coupled models and free-surface seepage analysis without mesh iteration

In a finite element model with ground water table, the classical method consists of using repeated iterations to adjust the water table to the geometry of the mesh while modifying the form of the elements. This method can be advantageously replaced by one which does not modify the mesh geometry but which defines the water table by means of the relationship : Hydraulic conductivity https://www.w3.org/1998/Math/MathML" display="inline"> = f (pore water pressure). This method allows the detailed and precise characteristics of the unsaturated zone above the water table to be taken into account and can be used in a model coupling the groundwater flow equation with the displacement equilibrium equation, hence introducing the effect of variations in permeability as a function of void ratio.