Sensitivity of fatigue assessment for offshore jacket platform to different pile–soil–structure interaction models

Abstract

ABSTRACT One of the main factors that affect the response of fixed offshore jacket platforms under wave loading is Pile–Soil–Structure Interaction (PSSI); thereby, it must be expected that different PSSI models may impact the fatigue damage assessments in harsh environments. In this study, the sensitivity analyses of fatigue damage results of an offshore jacket platform to different PSSI models have been performed by modelling piles up to the actual penetration depth with computationally demanding Beam on Nonlinear Winkler Foundation (BNWF) as the Reference Model (RM). Also, two different models were applied by analysing RM under Center-of-Damage (CD) wave (M2 and M4) as well as conducting the linear analysis (M1 and M3) to develop stiffness matrix and independent springs models. It was concluded that the independent springs model obtained by linear analysis provides acceptable fatigue damage compared to other alternative linear models in the case of large CD wave and shallow weak soil layers.