Effect of Dynamic Behaviour of Piles on Offshore Towers Response

Pile foundations supporting offshore platforms and marine structures are required to resist dynamic lateral loading due to wind and wave forces. The response of a jacket offshore tower is affected by the foundation flexibility and the nonlinear behaviour of the supporting piles. In the present study, the soil resistance to the pile movement is modeled using dynamic p-y curves and t-z curves to account for soil nonlinearity and energy dissipation through radiation damping. The model also allows separation at the pile soil interface. The wave forces on the tower members and the tower response are calculated in the time domain using a finite element package (ASAS). The tower response is calculated with emphasis placed on the effects of dynamic pile-soil interaction on the tower performance and the forces acting on the piles for a range of wave conditions.