Wind resources are rich in offshore areas of China

but the scale and efficiency of developing and utilizing offshore wind resources are greatly restricted due to the complex conditions of marine environment conditions. As the main environmental loads

wind

wave

and current play a decisive role in the normal operation of offshore wind turbines. In this paper

the time history of an offshore wind farm is simulated by using the harmonic superposition method

and the formula for calculating wave and current loadings are derived based on the nonlinear wave theory and the Morison equation. Then

the wind

wave

and current loadings are combined according to the Turkstra criterion. Based on the above theories

a three-dimensional finite element model for dynamic interaction of offshore wind power foundation and seabed is established under the combined wind

wave and current loadings. Based on this model

the dynamic horizontal displacement

the vertical stress of wind turbines tower

and the horizontal displacement

bending moment and shear force of the foundation are analyzed under different loading combinations. Moreover

the excess pore pressure response of seabed around the pile foundation is examined under the combined action of wind

wave

and current loadings. Finally

the influence of different load parameters on the excess pore water pressure of seabed is discussed. It can be concluded from the computation results that the wind loading has a great influence on the horizontal displacement at the tower top and the stress at the tower bottom; the wave and current loadings greatly affect the horizontal displacement of the foundation

and the bending moment and shearing force of the pile; and the wave loading is the most important factor affecting the pore water pressure of the seabed. The most unfavorable loading combination is the combination of the maximum wind loading and the maximum wave and current loadings with wave loading time history in this computation.