Evaluation of Seismic Performance of Offshore Wind Turbine Foundations with Slip Joints by Large Shaking Table Tests

In Europe, a monopile is the most commonly used foundation type for offshore wind turbines. Existing connections between the monopile (MP) and transition piece (TP) are generally bolts or grout, but another new method is the slip joint. In this method, the joints between the MP and TP are conically shaped and are simply joined together, which is expected to improve workability and reduce maintenance and management costs. In order to apply this structure in Japan, it is necessary to verify its seismic resistance. This paper reports the results of shaking table tests using a scaled specimen to verify the structural safety of the structure against earthquakes.