The project successfully executed its research plan, which was structured across several interconnected work packages, to investigate the performance of shared anchors for floating offshore wind turbines.
The initial phase of the project established the foundational parameters for the entire study. This involved a comprehensive analysis of load conditions, suitable anchor geometries for clay seabeds, and anchor installation considerations. This work, conducted in collaboration with the Norwegian Geotechnical Institute (NGI), resulted in a detailed set of prototype conditions that ensured the subsequent experimental and numerical studies were representative of realistic offshore environments.
The core of the experimental work was an extensive physical modeling campaign using the geotechnical centrifuge at Université Gustave Eiffel. A specialized experimental setup was designed to simulate the complex, multidirectional loading that shared anchors experience. A series of four centrifuge tests were conducted on 12 anchor models installed in reconstituted clay beds that replicated offshore soil conditions. This campaign produced a unique, high-quality dataset on the soil-anchor response under cyclic loading. From this data, experimental failure envelopes were developed, defining the load combinations that lead to soil failure and providing crucial stability contours for anchor design.
In parallel, numerical simulations were conducted using the Finite Element Method (OpenSees) to model the behavior of the anchors. These numerical models were carefully calibrated and validated against the high-quality data obtained from the centrifuge experiments. A significant achievement was the development of a fully validated set of numerical models capable of accurately predicting the stresses and deformations of the soil-anchor system. The project also implemented an innovative methodology using mobile photogrammetry to create Digital Twins, or virtual replicas, of the centrifuge models, enhancing the visualization and analysis of the experiments.
Finally, the validated numerical models were used to conduct extensive parametric analyses. These simulations explored a wide range of variables, including different anchor geometries and soil conditions. This work led to the project's main practical outputs: design guidelines and refined failure envelopes for shared anchors. These results have been consolidated into two peer-reviewed scientific articles, which are currently under review. The load data representative of shared anchor systems was also processed and made available in an open repository for use by other researchers and engineers.
