The Seepage and Soil Plug Formation in Suction Caissons in Sand Using Visual Tests

Abstract

The rapid development of offshore wind energy in China is becoming increasingly relevant for movement toward green development. This paper presents the results of visual tests of a suction caisson used as foundation for offshore wind turbines. The distribution of hydraulic gradients of sand at the mudline in the caisson was obtained to find out the relationship with the heights of soil plugs. The relationship equation was proposed and obtained by using quadratic regression, guiding project designs, and construction. It was found that there was no soil plug in the caisson when small suction was applied during the suction penetration. The relationship between the heights of the soil plugs and the hydraulic gradient of the soil was proposed and obtained by using quadratic regression to predict (roughly) the height of soil plugs in suction caissons in sand during suction penetration. The influence of settlement outside caissons on the soil plug was found to decrease as the buried depth rose.

Experimental Investigation of Skirted Foundation in Sand Subjected to Rapid Uplift

“…1. Suction generation between the top plate of the skirted foundation and the soil plug confined by the skirts Kelly et al (2004), Luke et al (2005), Kakasoltani et al (2011), Hung et al (2017), Zhai and Li (2017), and Xie et al (2020).…”

Special Issue on “Buildings and Structures under Extreme Loads”

“…Among others, a extreme natural event is certainly represented by windstorms. In this Special Issue, wind load modelling and design is mainly addressed by [6][7][8], while [9] describes the results of a visual test carried out on a suction caisson that support offshore wind turbines. Finally, the last natural hazard analyzed in the Special Issue is snowdrift.…”