Bearing capacity of modified suction caissons in clay overlying sand under monotonic horizontal loading

• Published in: Ocean engineering 2024-10, Vol.309, p.118602, Article 118602
• Main Authors: Zhao, Jipeng, Li, Dayong, Zhang, Yukun, Wu, Yuqi, Qiu, Peng
• Format: Article
• Language: English
• Subjects: Earth pressure; Layered soil; Modified suction caisson (MSC); Monotonic horizontal loading; Numerical modeling
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2024.118602

The modified suction caisson (MSC) is an innovative foundation for fixing offshore wind turbines, consisting of an internal caisson (IC) and an external skirt (ES). In this study, the Plaxis3D is conducted on the bearing capacity of the MSC in clay overlying sand under monotonic horizontal loading. The parameters of the aspect ratio of the IC, the size of the ES, the clay thickness, and the soil strength are considered. Results show that the horizontal ultimate bearing capacity of the MSC decreases as the length ratio of the ES to IC decreases. Moreover, the width of the ES enhances the horizontal bearing capacity of the MSC higher than the length of the ES. With the increase of the clay thickness, the rotation center of the TSC and MSC exhibits two and three stage change patterns, respectively. When the clay and sand are the inhomogeneous soils, the horizontal ultimate bearing capacity of the MSC is enhanced by 8.96% compared to the homogeneous soils. Additionally, the passive and active earth pressures around the MSC are mainly generated at the front and rear side of the loading direction, respectively. This study will provide theoretical guidance for the design of the MSC. •The bearing capacity of the MSC is studied in clay overlying sand.•The variation law between the rotation center of the MSC and the clay thickness is obtained.•The distribution characteristics of earth pressure around the MSC is revealed.