A Coupled Model for an Offshore Pile, Seabed and Seawater Interaction

LU, J.-F. AND JENG, D.-S., 2007. A coupled model for an offshore pile, seabed and seawater interaction. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 389 – 393. Gold Coast, Australia, ISSN 0749.0208 A coupled model is developed to investigate the dynamic interaction between an offshore pile, poroelastic seabed and sea water. The pile and the seabed are treated as saturated porous media described by Biot’s dynamic theory. The sea water is regarded as an acoustic medium which is characterised by the Helmholtz equation. Three boundary element formulations are constructed for the pile, the seabed and the sea water, respectively. The three boundary element method formulations and the continuity conditions (stress and displacement) between the pile, the seabed and the sea water are used to formulate the coupled model for the system. Airy linear wave theory is used to evaluate the external force applied on the pile and the seabed due to the incident and the scattered water waves. The dynamic response of the system is calculated by the coupled boundary element method formulation. A numerical example is used to demonstrate the capacity of the coupled model.