Model tests for soil plug heave in installation of suction caisson on silica sand

Abstract

Excessive soil plug heave that occurs during installation plays an important role in successful installation of suction caisson. However, the mechanism of sand heave has not been fully investigated. In this study, model tests were performed to investigate the mechanism of sand heave during suction caisson installation. A test apparatus including half-caisson model, which can enable visualization of the soil movement through the window in the container during installation, was developed to observe the soil heave directly. Deformations of soil were captured by a digital camera and analyzed by using particle image velocimetry (PIV) method. The results showed that the majority of sand heave was caused by the expansion of sand plug it-self depending on locations inside the caisson.