1D INFINITE ELEMENT FOR DYNAMIC PROBLEMS IN SATURATED POROUS-MEDIA

A fully coupled 1D infinite element for frequency domain analysis of w ave propagation problems in unbounded saturated porous media is presen ted. The element wave propagation function is derived using an analyti cal solution for Blot's formulation (1962). The effectiveness and the accuracy of the infinite element proposed are demonstrated through a s imple wave propagation problem in a semi-infinite soil column subjecte d to a harmonic surface loading. It is shown that an accurate represen tation of the problem can be obtained by coupling the conventional fin ite elements with the proposed infinite element. The accuracy of the s olution significantly deteriorates when free or fixed boundary conditi ons are imposed at the truncated boundary instead of the infinite elem ent. (C) 1997 John Wiley & Sons, Ltd.