Centrifuge shaking table tests on offshore wind turbine bucket foundation in mildly inclined liquefiable seabed

Increasing number of offshore wind farm projects with wind turbines supported by suction bucket foundation in mildly sloping sandy seabed have being planned in earthquake-prone areas. Hence, it is crucial to evaluate the seismic performance of suction bucket foundations for offshore wind turbines in such liquefiable ground, especially considering the interaction between the bucket and both outside and inside bucket soil. Based on a pair of centrifuge shaking table tests, the seismic response of the bucket foundations and turbines in liquefiable ground is evaluated in this study. The dynamic response of soil, foundation, and turbine are presented. The test results indicate that the horizontal displacement of mildly sloping liquefiable seabed during earthquakes can results in excessive displacement and rotation of the bucket foundation. The influence of inside-bucket soil on foundation and turbine response, and especially on the kinematic and inertial interactions of the system are analyzed in detail. The analysis results indicate that inside-bucket soil plays an important role in stabilizing the foundation-turbine system during earthquakes, restricting the displacement and rotation of the foundation and the acceleration of the turbine.