EVALUATION OF 3-FIELD AND 2-FIELD FINITE-ELEMENT METHODS FOR THE DYNAMIC-RESPONSE OF SATURATED SOIL

The three-field formulation u-p-U is presented and is applied to solve dynamic equations for saturated porous media. In order to evaluate the accuracy and the performance of this three-field approximation, the u-U and the u-w formulations are also considered and a few one- and two-dimensional examples are solved using the three methods. Problems for which both the pore fluid and the solid grains are incompressible are also considered and are solved using the u-p-U approximation. Accuracy was determined by a comparison of the finite element results with the analytical solution given by Gajo and Mongiovi,19 for a wide range of permeability.