The Effects of Pile Shape on the Lateral Capacity of Monopiles used as Wind Turbines Embedded in Sand Deposits

Offshore wind power generators are potential for generating renewable energy in the world. Nevertheless, foundation systems that are capable of withstanding higher load capacities are required to generate more energy per structure. In recent years many structures like piled footings, un-piled footings, tripods and tetrapod foundations have been extensively investigated for offshore wind turbines. Although many of these studies have been successful, still most wind farms around the world are constructed by conventional monopile structures, which are mainly circular hollow steel tubes. In this paper the ultimate lateral capacity and the stiffness of a monopile structure used as an offshore wind turbine installed in shallow waters is investigated by the aid of finite element analysis. The response of the structure is investigated through three dimensional finite element analyses in sand deposits with considering an elasto plastic material for the monopile. Moreover, the stiffness and the ultimate lateral capacity of a circular pile/tower is compared with the results obtained from a square, rectangle and a regular hexagon pile/tower to illustrate that a squared pile/tower configuration has the highest stiffness and ultimate lateral capacity compared to all other configurations.