Numerical simulation of cone penetration tests inside suction caisson foundations in sand

Offshore wind is increasingly utilised as a renewable energy source. A growing number of bottom fixed wind turbines installed offshore are supported by suction caisson foundations. The suction-assisted installation remains a source of uncertainty towards the in-service performance due to the unknown postinstallation soil plug state. Cone penetration tests within the suction caisson can help to improve the reliability. Therefore, cone penetration tests were employed in centrifuge tests to investigate the plug state in a previously installed suction caisson. However, the performance of a cone penetration test in a smallscale experiment is connected to uncertainties: A relatively large diameter device is required to conduct the cone penetration test - especially in a centrifuge test. Different finite element models are developed in order to visualise and investigate a cone penetration test inside a suction caisson. The numerical analysis results are validated through the back-calculation of centrifuge cone penetration tests. The results of the simulated cone penetration tests inside a suction caisson are evaluated and compared to the centrifuge experiments. This investigation reinforces the scope of the centrifuge experiments and emphasises a considerable effect of the pressure transferral through the caisson lid in the soil plug state. Hence, the results of this study reduce existing uncertainties regarding possible suction installation effects on the in-service performance of caisson foundations. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.