Floating offshore wind turbines (FOWTs) rely on suction anchors as a key foundation system, providing high efficiency and cost-effectiveness in deep-water installations. The performance of suction anchors is influenced by various factors, including geometric parameters, installation conditions, and soil resistance. Among these, tilt (δ) and misorientation (β) of the anchor during installation can significantly affect the pullout capacity, yet most existing studies have investigated these factors individually, without considering their combined effects. This study aims to evaluate the combined influence of tilt and misorientation on the pullout capacity of suction anchors for FOWTs. Both a geometric method and numerical analysis are employed to quantify the reduction in pullout capacity under various tilt and misorientation scenarios. The geometric method provides a simple and practical estimation, while the numerical analysis incorporates soil stress–strain behavior, anchor–soil interface effects, and progressive failure mechanisms. A comprehensive comparison between the two approaches allows verification of the geometric method and identification of conditions where its simplifications may lead to overestimation, particularly at large misorientation angles. From a practical engineering perspective, the study proposes allowable limits for tilt and misorientation based on a conservative 3% pullout capacity reduction criterion. This provides a useful guideline for installation tolerances, bridging the gap in existing literature and industry standards. Although the present study focuses on static loading conditions, it is noted that real FOWT installations are subjected to dynamic environmental loads, including wind, waves, and currents. Future research should incorporate dynamic analyses to fully capture the behavior of suction anchors under operational conditions.
Jung et al. (Mon,) studied this question.