TEST AND FEA OF INSTALLATION AND AXIAL BEHAVIOR OF SUCTION CAISSON IN CLAY

Suction caissons have mainly been used as foundations to support offshore structures in deep water. As the suction used to install suction caissons is dependent on water depth, their applications in shallow water are more challenging as there is less suction force that can be used to install the caissons. Unfortunately, there have been no standards for suction caisson bearing capacity design up to now. Additionally, the issues of caisson-soil interaction and each caisson parts bearing behaviors have been rarely investigated. In this paper, efforts were made to investigate suction caissons as a type of foundation for underwater structures. Model tests were carried out to study the behavior of a suction caisson installed in different types of consolidated soils. The suction effect on the soil inside the caisson (i.e., soil plugs) was also investigated. Engineering measures were suggested for caisson installation in clay. Based on the FEM, 3D numerical analysis is performed to simulate the working mechanism and evaluate the bearing capacity behavior of a suction caisson, on the basis of which a calculation method is presented for caisson vertical bearing capacity. The conclusions can provide references for caisson bearing capacity design.