Bearing capacity of monopile-bucket composite foundation in sand-over-clay under V-H-M combined static loads

Abstract

With the rapid development of offshore wind power energy, the requirements for the bearing capacity of offshore wind turbines have been obviously stricter. In response to this subject, an innovative monopile-bucket composite foundation consisting of an embedded pile and a suction bucket is proposed in recent years, and the bearing mechanism of this new type of composite foundation in double-layer soils has not been investigated comprehensively. To explore the bearing capacity and failure mechanism of this composite foundation embedded in sand-over-clay under V-H-M combined static loads, a series of the 1-g model tests are firstly conducted in this paper. Then, the experimental tests under different common loading conditions are validated with 3D finite element analysis. Finally, parametric analysis has been performed to investigate the behaviors of the composite foundation considering different foundation configurations (geometric dimensions, soil properties, loading pattern, etc.). In detail, the load transfer mechanism between single pile and suction bucket are also discussed. Therefore, the composite foundation is demonstrated that has great potential in bearing performance compared to the traditional monopile and suction bucket. This work may pave the way for the guidelines of engineering design and applications of monopile-bucket composite foundation in marine environment.