Influence of Lateral Load on the Seismic Behavior of Pin-Piled Jacket Structures for Offshore Wind Turbines Founded in Liquefiable Soils

With the offshore wind industry moving into deeper waters, pin-piled jacket structures have become the preferred foundation solution for wind farm developers. The stability and performance of these structures under seismic loading, particularly in liquefiable seabed conditions, require detailed investigation. Recent DNV guidelines emphasize the need to account for operational wind and wave loads in combination with seismic forces. Through dynamic centrifuge modeling, this research presents the seismic performance of jacket structures supported on pile foundations, with and without operational loads. The model jacket structure was embedded in a layered seabed, with dense sand underlying loose, liquefiable sand. The results show that operational loads significantly increase residual settlement and rotation during seismic events. Additionally, a substantial increase in global rotational stiffness was observed postseismic loading. These findings underscore the importance of considering operational loads in the seismic design of jacket structures in liquefiable soils to ensure long-term stability and serviceability into the postearthquake period.