Numerical Analysis Of Bucket Foundation Suction Penetration Seepage Field

The bucket foundation is widely used in offshore projects. Because of short developing time in China, many problems of design and installation need to be resolved. Finite element method and particle flow method are used to analyze the macroscopic and microcosmic seepage field of the soil in the bucket foundation while suction penetration and the physical parameters are established.First, the two-dimension finite element program is used to calculate the seepage parameters distribution of the ocean floor deposits in the bucket foundation, such as the head of water, the seepage force and the seepage velocity. Then, the process of microscopic seepage is simulated by particle flow method successfully. At last, the strain of penetrative marine soft clay has been calculated by J₂ flow theory and isotropic. According to the strain of penetrative marine soft clay and the volumetric strain, based on the definition of permeability and porosity, physical parameters are established. The developing process of permeability and porosity are analyzed according to calculated results.The head of water is homogenous distribution inside the bucket foundation. The radial seepage velocity is mainly distributed around the end of the bucket, so the influence region is getting smaller while suction penetration. The axial seepage velocity has a great influence both inside and outside the bucket foundation, and it is the key element to study the penetration resistance and soil plug formation. Particle flow simulation and the calculation of the physical parameters are based on the results of the seepage force. Because of the radial confine, the axial strain is primary. Permeability and porosity increase along with the increasing of the suction pressure and penetration depth. The strain of the soil particle is much smaller than the soil skeleton, so the physical parameters change in accord with the strain of the soil skeleton.The research is meaningful reference for the theoretic calculation, the bucket foundation's design and construction.