On fluid-filled mixture model for suction pile foundation analysis

Abstract

The purpose of this study was to investigate the installation water pressure of the offshore wind turbine suction bucket caisson foundation. The fluid-filled mixture theory was used in the study and the theoretical equations are derived from the basic theory of ocean fluid dynamics and flow in porous media and they were solved by finite difference methods. Benchmark verification was performed prior to further simulation cases. Numerical examples were made based on several penetration depths and different suction pressures. Different boundary conditions were tested and the most reasonable boundary conditions were proposed. Suction induced stresses in response to various suction pressures and penetration depths were investigated. The overall lateral resistance and possible piping potential were studied. The frictional stress and bearing capacity on the outside of the caisson are greater than those on the inside. Even the critical suction pressure is given and the penetration depth increases to 2.5 m, the suction induced stress at the outer corner of the caisson tip only increases to 70% of the static effective soil stress and does not reduce the effective vertical soil stress to zero, and no piping is occurred.