Lateral bearing behavior and failure mechanism of monopile-bucket hybrid foundations on sand deposit

Abstract

With the development of OWT technology, the requirement for bearing capacity of OWT is becoming stricter. A new type of monopile-bucket hybrid foundation has been recently proposed. As the bearing behavior and failure mechanism of the hybrid foundation have not been investigated comprehensively, laboratory experiments and numerical analysis of the monopile-bucket hybrid foundation subjected to H-M-T combined loads in sand are finished in this paper. Firstly, the model tests were carried out to explore the lateral bearing performance of the hybrid foundation with different loading eccentricity, skirt heights and pre-torque loads. Then, based on the numerical analysis, a quantitative analysis is proceeded to find out the influence of different factors on the bearing performance of the hybrid foundation in detail. The results show that, the lateral bearing capacity of the hybrid foundation is greater than the sum of bucket foundation and monopile. It's also found that the torque load has a strong weakening effect on the lateral bearing capacity of the hybrid foundation. Finally, an empirical calculated formula for calculating the lateral bearing capacity of the hybrid foundation in sand is proposed, which may provide a valuable engineering application reference for monopile-bucket hybrid foundation in sand under H-M-T combined loads.