Assessment of suction caisson drained tensile capacity through multiscale physical tests
Suction-installed caissons in multiple arrangement have been recently used as foundations for support structures of offshore wind turbines. The design of these foundations is challenging due to the geotechnical issues related to the suction-assisted installation, the complexity of the load transfer mechanisms and the restricted accessibility to field data. Lately, international guidelines and German norms addressing the geotechnical design of suction caissons for offshore wind applications have been released. Even though these publications have partially increased the confidence in using these foundations, scientific efforts aiming at a better geotechnical understanding and structural optimization are still needed. This paper presents a contribution to improve the geotechnical modelling of suction caissons based on the concept of physical modelling across the scales. The analysis focuses on the evaluation of the drained tensile capacity of suction caissons in saturated dense sand. For this purpose, the results of a single-gravity multiscale experimental campaign with suction-installed single caissons at small- and large-scale are analyzed. The test results are used to evaluate scaling approaches as well as design methods for tensile capacity. It is shown that physical modelling across the scales can enhance the comprehension of geotechnical mechanisms and potentially improve the current design methodologies.