As offshore wind energy industry advances into deeper water recently, jacket foundations become one of the predominant support structure types for far-sea wind farms. To ensure the safety and reliability of offshore wind turbine (OWT) jacket foundations in the complex environments of far-seas, the investigation of their resistance capabilities to extreme ocean wave is essential. In this study, the OWT jacket foundations in the sea area of Cangnan and Lianjiang are adopted to conduct a typical case study. This study employs a full-scale jacket foundation to carry out some full-scenario, large-scale hydrodynamic numerical simulations considering the combined action of wave and current. It is revealed that for OWT jacket foundations in Cangnan and Lianjiang, China, under an extreme condition with approximately 26 m wave height and 18 s wave period, the peak wave impact and horizontal force on the jacket foundation are approximately 190 kPa and 18,000 kN, respectively. Furthermore, this study discusses the wave profile evolution characteristics around the jacket foundation and the correlation between wave run-up and wave height. These findings provide a good case study and technical reference for the full-scale fine simulation of wave forces on OWT jacket foundations in far-sea areas.

This study presents the design and performance assessment of suction anchor foundations for an integrated offshore wind–solar–aquaculture system located in Jiangsu Sheyang, China. The project represents one of the first practical demonstrations of coupling renewable energy production with large-scale marine aquaculture on a shared floating platform. Using three-dimensional numerical simulations in FLAC3D and ABAQUS, the study evaluates the anchors’ bearing capacity, structural safety, and fatigue performance under ultimate (ULS), accidental (ALS), and fatigue (FLS) limit states. The analysis incorporates site-specific geotechnical conditions, seabed scour, and installation deviations, providing a realistic framework for foundation design in layered coastal sediments. Results confirm that the suction anchor system meets international safety requirements (DNV, CCS) and maintains robust performance throughout its service life. The findings demonstrate that scour depth and installation accuracy are critical factors governing anchor reliability and offer practical insights for updating offshore foundation design standards in future multifunctional renewable–aquaculture developments.

This study introduces an innovative deflection-controlled design method (DCM) for evaluating the bearing capacity of offshore mono-bucket foundations (MBFs) in clay, integrating advanced numerical simulations using FLAC3D with the modified cam clay (MCC) soil model. Departing from conventional ultimate bearing capacity approaches, the proposed method prioritizes serviceability limits by constraining foundation deflections to ensure optimal structural performance and turbine efficiency. A systematic investigation revealed that the MBF performance is predominantly governed by eccentricity ratios and soil–structure interaction, with vertical loads exhibiting a minimal impact in a serviceability limit state. Key findings include the following: (1) the rotation center (RC) stabilizes at approximately 0.8 times the skirt length (L) under loading; (2) thin, deep MBFs (aspect ratio > 1.0) exhibit up to a 30% higher bearing capacity compared to wide, shallow configurations; (3) increasing eccentricity ratios (ε = 0.31–1.54) enhance the moment capacity but reduce the allowable horizontal force by 15–20%; (4) compressive vertical loads (υ = −0.30) slightly reduce the normalized bending moments (ω) by 5–10% at low eccentricities (ε < 0.5). The numerical framework was rigorously validated against centrifuge test data, demonstrating high accuracy (error < 3%) in predicting foundation behavior. By bridging geotechnical mechanics with practical engineering requirements, this study provides a robust and efficient design framework for MBFs, offering significant improvements in reliability and cost-effectiveness for offshore wind turbine applications. The proposed DCM successfully guided the design of an MBF in southeastern China, demonstrating its efficacy for use with homogeneous clay.

Pile–bucket foundation is a newly developed offshore wind turbine supporting structure created by combining a monopile and a bucket foundation. Current research mainly focuses on its bearing characteristics in homogeneous soil layers (e.g., pure sand and pure clay); however, field stratigraphy is normally in a layered distribution, which may alter the bearing mechanism of the pile–bucket foundation and lead to inconsistency in the prediction of the bearing capacity. In this study, three-dimensional finite element simulations are performed, and the static lateral bearing characteristics of pile–bucket foundation in layered sand–clay strata are investigated considering the impact of monopile size, bucket size, and sand/clay thickness ratio (H_s/H_c). Numerical results indicate that an increase in sand layer thickness could help increase the bearing capacity of the pile–bucket foundation, especially as H_s/H_c increases from 0.5 to 1. Then, hyperbolic p-y models are introduced to calculate the lateral load–displacement curves of the pile–bucket foundation, which is divided into three sections: the bucket section and pile section in sand and clay, respectively. The two controlling factors of the p-y model, the initial stiffness and the ultimate lateral resistance, are modified based on numerical results. The modified p-y model provides satisfactory predictions of the pile deflection and the moment distribution of pile–bucket in layered sand–clay strata and could serve as a framework in more complicated soil deposits, such as clay-over-sand or multi-layer.