Bearing Characteristics of Tripod Bucket Jacket Foundation for Offshore Wind Turbines in Sand under Monotonic Loads

Tripod bucket jacket foundation is an alternative foundation solution for deep-sea wind farms. This paper analyzes and compares the bearing characteristics of two tripod bucket jacket foundations with different height-diameter ratios, the tripod suction pile jacket foundation (TSPJF) and tripod bucket jacket foundation (TBJF), under different monotonic loads. The bearing modes of the two foundations under the vertical loads are different. The ultimate vertical load is mainly borne by the inside frictional resistance for the TSPJF, while it is mainly borne by the lid resistance for the TBJF. The foundations will take place translation and rotation under horizontal load. Under the positive x-axis loading, the vertical resistance of the TSPJF and TBJF is mainly composed of the soil resistance on the 1# bucket lid, the inside and outside frictional resistance. Under the negative x-axis loading condition, the vertical resistance is mainly composed of the inside and outside frictional resistance of buckets. The ultimate moment capacities of the TSPJF and TBJF in loading of the single bucket in compression is significantly larger than that in loading of the single bucket in tension. The failure mode of the TSPJF and TBJF in loading of the single bucket in tension is the pull-out failure of the bucket in tension.