Abstract Considering the deficiencies of the traditional monopile foundation for offshore wind turbines (OWTs) in severe marine environments, an innovative hybrid foundation is developed in the present study. The hybrid foundation consists of a traditional monopile and a wide–shallow bucket. A series of numerical analyses are conducted to investigate its behavior under the static and dynamic loading, considering various loading eccentricities. A traditional monopile with the same steel volume is used as a benchmark. Although the monopile outperforms the hybrid foundation in terms of the ultimate moment capacity under each loading eccentricity, the latter can achieve superior or the same performance with nearly half of the pile length in the design loading range. Moreover, the horizontal load and moment are mainly resisted by the bucket and the single pile in the hybrid foundation respectively. The failure mechanism of both the hybrid foundation and the monopile is excessive rotation. In the rotation angle of 0.05 rad, the rotation center is located at the depth of approximately 0.6–0.75 times and 0.65–0.75 times the pile length for the hybrid foundation and the monopile respectively. The increasing loading eccentricities can lead to increasing moment bearing capacity, increasing initial stiffness and upward movement of the rotation center of the two foundations, while decreasing load sharing ratio of the single pile in the hybrid foundation. Three scenarios are considered in investigating the dynamic loading behavior of the hybrid foundation. Dynamic response results reveal that addition of the bucket to the foundation can restrain the rotation and lateral displacement effectively. The superiority of the hybrid foundation is more obvious under the combined wave and current loading.

中文翻译：

---

海上风力发电机混合基础的静态和动态载荷行为

摘要 针对恶劣海洋环境下海上风力发电机组（OWTs）传统单桩基础的不足，本研究开发了一种创新的混合基础。混合基础由一个传统的单桩和一个宽浅的铲斗组成。考虑到各种加载偏心率，进行了一系列数值分析以研究其在静态和动态加载下的行为。以具有相同钢体积的传统单桩作为基准。虽然单桩在每个荷载偏心下的极限弯矩能力优于混合基础，但后者在设计荷载范围内几乎一半的桩长即可获得优越或相同的性能。而且，水平荷载和力矩主要分别由混合基础中的铲斗和单桩抵抗。混合基础和单桩的破坏机理都是过度旋转。在 0.05 弧度的旋转角度下，旋转中心分别位于混合基础和单桩桩长的 0.6-0.75 倍和 0.65-0.75 倍深度处。荷载偏心的增加会导致弯矩承载力增加，初始刚度增加，两个基础的旋转中心向上移动，同时降低混合基础中单桩的荷载分担比。在研究混合基础的动态载荷行为时考虑了三种情况。动力响应结果表明，在基础上增加铲斗可以有效抑制旋转和侧向位移。混合基础的优越性在波流联合荷载作用下更加明显。