An innovative bionic offshore wind foundation: Scaled suction caisson

This paper presents an innovative scaled suction caisson (SSC) for fixing offshore wind turbines (OWTs) to enhance its anti-overturning bearing capacity. The outer wall of the SSC is constructed with a scaled bionic structure referring to snakeskin scales, reducing resistance to installation and increasing pullout capacity, which is verified by model tests that the SSC requires less applied suction and provides higher horizontal bearing capacity in sandy soil compared with the traditional suction caisson (TSC) under the same caisson diameter and height. Also, model test results reveal that the SSC can reduce the height of soil plug and the scaled structure can effectively limit the SSC inclination in comparison to the TSC. Additionally, numerical results show that the ultimate bearing capacity for the SSC increases rapidly when the friction factor lambda between the caisson wall-soil interface ranges from 0 to 0.2. Moreover, the sidewall of the SSC dissipates less energy than that of the TSC due to the small displacement of soil near the sidewall. This study confirms that the SSC can eliminate grouting in the space between the top of the soil plug and the bottom of the cap, thus reducing the construction period, construction costs and avoiding marine pollution.