Evaluation of Seepage Flow during Installation of Suction Caisson Foundation in Homogeneous Sand and Sand Overlaying Inclined Clay

Suction caissons have been widely considered as foundations in offshore engineering. Installation of a suction caisson foundation in seabed soil is affected by seepage conditions. This study aims to investigate the seepage behavior during caisson installation in sand and sand overlaying inclined clay. Small-scale 1g model tests and numerical studies using finite-element analysis were used to determine the variation and distribution of excess pore water pressure generated by suction in a homogeneous sand. A series of three-dimensional (3D) finite-element models were also undertaken in which installation is considered through sand into an inclined clay layer to simulate the behavior of seepage. The results of this study, which may not be valid for larger scale models, indicate that the inclined impermeable layer (clay) below the sand is affecting the flow in sand, and the influence is dependent on the distance of the impermeable layer to the caisson tip.