The optimisation of anti-overturning capacities for tripod suction bucket foundations in clay. (15th November 2022)

• Record Type: Journal Article
• Authors: Qiu, Changlin; Wang, Weichen; Yan, Yue; Fu, Dengfeng; Yan, Shuwang
• Is Part Of: Ocean engineering. Volume 264(2022)
• Publication Date: 2022-11-15
• Subjects: Offshore bucket foundation -- Tripod bucket foundation -- Anti-overturning capacity -- Clay -- Failure mechanism; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.112496
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: The tripod bucket foundation that combines three single buckets within a triangular shape, is an emerging alternative foundation solution to support offshore wind turbine in deep water. Its performance of geotechnical capacity, especially under overturning loading, is increasingly concerned by offshore engineering. This paper reports an investigation to anti-overturning capacity of tripod bucket foundations in clay, with focus on the relatively larger foundation embedment. The kinematic mechanisms of the whole foundation system are systematically examined against increasing foundation spacing, considering the influence of foundation embedment. Based on these, an efficient method to predict the anti-overturning capacity is proposed, covering a wide range of embedment, spacing and soil strength heterogeneity. Finally, some recommendations of optimization for sizing foundation are offered, with the example application demonstrated. Highlights: 1. The evolution of failure mechanisms of tripod bucket foundations in clay against foundation spacing at different embedment is investigated under overturning loading, with global failure, transient failure and separate local failure modes identified. 2. The pull-push combined with rotational failure mechanism can be mobilised under high spacing ratio, with the contribution from rotational failure mechanism to anti-overturning capacity occupying around 12.6%–30%. 3. A method is developed to estimate the anti-overturning capacity of tripod bucket foundation in clay, with some practical considerations and recommendations of optimizing foundation design provided.