Document Type : Research Article
Civil Engineering faculty, Semnan University
In comparison with monopile foundation, bucket foundation is an economic option to reduce the construction costs of offshore wind turbines. It is similar to a suction caisson, which is driven into the soil like an upside-down bucket. Various available scientific researches have stated that how the length of skirt affects the ultimate capacity (qult) of bucket foundations that are utilized for different kinds of offshore applications. The experiments and 3D FE analyses have been performed to assess the ultimate vertical load capacity (Vult) of bucket foundations. The experiments were conducted on loose sand and it shows that as the length of skirt increases, the qult enhances. A conceptual relationship as a depth factor was suggested to estimate the Vult of bucket foundations on the sand with regard to embedment ratio and soil friction angle. The FE analysis results have shown that the inner soil in the bucket foundation approximately behaves as a rigid body under the vertical loading. Therefore, it might be supposed that with similar dimension, the qult of embedded and bucket foundation is close. Moreover, it was found that due to the increase in the slip line length of bucket foundation, the foundation failed in greater settlement than surface footing.