Numerical Simulation Study on Seismic Response of High-Cap Batter Pile Group Foundations for Offshore Wind Turbines

At present, high-cap batter pile group foundation has been widely used in offshore wind turbines. However, the practice for designing this structure in high seismicity areas is still limited. This paper reports on numerical model simulation of high-cap batter pile group Foundation for offshore wind turbines subjected to earthquake load. The model is composed of seabed soil, batter pile group, pile cap, tower, nacelle and fan blades. The objectives of the simulations are to investigate: (1) the deformation and inner force of each batter piles; (2) the influence of pile inclination degree on the seismic response; and (3) the influence of pile diameter on the seismic response. The simulations indicated that the maximum displacement and maximum bending moment under seismic action do not differ much among the batter piles because they are limited by the pile cap. Increased inclination of batter piles reduces the deformation of piles in the submerged section and has little effect on piles in the soiled section. The increase of pile diameter can enhance the bending strength of the pile body and effectively reduce the structural displacement.