In the last decade, offshore wind industry has grown exponentially, especially in Europe where is installed more than 80% of the total power of the active offshore wind turbines. In order to bring cost of wind power to a competitive level, dimension and capacity of the new wind turbines are increasing over the year, leading the foundations designers to new engineering challenges. In the offshore environment about 20% of the total cost of a wind turbine is represented by the foundation, which today is largely constituted by large diameter piles often larger than 6m. The need to reduce the foundation cost and increase the pile diameter led to the installation of piles with an increasing diameter to pile wall thickness over the year.