Seismic response of offshore wind turbines supported on Monopiles and Suction Buckets: Numerical modelling and soft computing study

In this study, a coupled numerical modeling and soft computing was carried out to investigate the seismic response and liquefaction resistance of two common types of foundations used for offshore wind turbines (OWT), namely the Monopile and Suction Bucket Foundations under combined loading of wave, wind and earthquake. A series of fully coupled non-linear dynamic analysis was performed using FLAC-3D to produce the database required in the soft computing procedure by evaluating the effect of different factors such as foundation's geometrical properties (foundation's type and its aspect ratio), soil properties (relative density and depth of liquefiable layer) and the input ground motion parameters (frequency and amplitude). Parameters of SANISAND constitutive model were calibrated using centrifuge studies performed on OWTs. Afterwards, genetic algorithm (GA) was used to develop prediction models for prediction the seismic response parameters, especially the maximum value of tower's rotation, which was verified against the results of centrifuge experiments. •Preforming a comprehensive parametric study on the seismic response of OWT foundations in liquefiable soil.•Performing a series of advanced fully coupled non-linear dynamic analysis using FLAC-3D.•Calibration of SANISAND parameters using centrifuge experiments.•Comparison of the obtained results, by elaborating the mechanisms behind the observed behavior.•Using genetic algorithm to develop prediction models for the seismic response parameters, verified by centrifuge experiments.