Composite bucket foundation which is wide and shallow is a new kind of foundation. The fluctuating pore water pressure around the foundation has bad influence on the safety of wind turbine under the wind

wave and current loads. In order to investigate the dynamic response of the foundation under the wind

wave and current loads

the numerical analysis is carried out. The combined effect among the wind

wave

current loads acted on the wind turbine structure and the subgrade is simulated reasonably based on the accurate simulation of various loads

and the model of the dynamic response of bucket foundation is presented with the three-dimensional finite element method. According to the numerical model

the dynamic response pattern of subgrade including the laws of the pore water pressure fluctuation and liquefaction locality around the bucket foundation are identified. It can be concluded that the liquefaction depth in the vicinity of composite bucket foundation increases with the growth of the saturation

permeability

wave period and water depth

and it decreases with the addition of the Poisson ratio.