Evaluation of three‐ and two‐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.