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By taking the importance of seepage parameters into account during the suction process, a comparison analysis of seepage field between bucket foundations with (C-BF) and without multiple subdivisions inside (N-BF) is performed in this paper, with the consideration of tilt adjustment as well as the complexity in underwater soil. Scaled model experiments were conducted at first to acquire the excess pore water pressure μ e , and then the law of three-dimensional heat conduction was used to simulate the seepage field and the parameters of the two models. The results of simulations were compared with those of the model experiment, and it is shown that the computational results agree well with those of experiments; N-BF is more sensitive to the tilting of the bucket body than C-BF; the layered soil can protect the seepage filled with limited hydraulic gradient and seepage flux; basically the seepage field variations with the same internal structure under different working conditions have their own regularities.

An integrated finite element model(FEM)of offshore wind tower-foundation-soil is established by ABAQUS, where a large-scale composite bucket foundation with seven compartments inside is applied to supporting the upper wind tower. The dynamic response of the structure-foundation system is studied under three seismic waves with the same peak ground acceleration of 0.035g. It can be seen that the dynamic response increases at the beginning with the structure height, then it decreases because the structural damping increases due to the mass effect of the upper wind turbine generator system. It is shown that the anti-liquefaction capacity of the soil inside and underneath the foundation is improved owing to the high overburden pressure of the upper structure and the constraint effect of the bucket skirt and subdivisions. Moreover, the liquefaction resistance of the soil inside the middle compartment is improved to a higher degree than that inside the side compartments.

In this paper, the influential design factors of wide-shallow composite bucket foundation for 3 MW offshore wind turbine are systematically studied by numerical simulation. The results show that the bucket diameter is larger than 27 m in general, and the range of 7–12 m is appropriate for cylinder height. In particular, the bucket foundation with diameter of 30 m and cylinder height of 10 m is suitable for most soils. Under ultimate loads, the bucket diameter and elasticity modulus of soil have major effects on the deformability of bucket foundation, while the influence of friction coefficient between the bucket and soil is relatively slight.