Study On The Design And Selection Of Offshore Wind Turbine Foundation Structure

The high cost is one of the main factors restricting the development of offshore wind farm construction. And the rate of foundation structure cost is very large in total cost, 20% to 30% approximately. Hereby, more and more attention is paid on looking for the technical-feasible and low-cost foundation structures of wind farm. Currently, a series of related technique researches and equipment development of offshore wind farm construction in our country are still at a preliminary stage. Therefore, it is significant to summarize and master advanced and known results of developed countries, and then to do the foundation structure design and selection research for wind turbines.Aiming at the problems of the design of offshore wind turbine foundation structure, this paper contrasts and analyses the common foundation structures (such as gravity, pile foundation, jacket, pressure barrel, floating and so on), and does research on construction techniques and its working condition of all foundations mentioned above, and then discusses the selection method of the foundation structure. According to the seafloor soil condition and the sea-condition of offshore wind farm in Jiangsu Dafeng and Shandong Weihai, foundation structures which adapted to different water depth conditions are presented for1.5MW and 3.0MW wind turbine firstly. And then stress performance and dynamic characteristic are analyzed basing on the finite element software ABAQUS. Secondly, basing on Approximate Calculation Preparation Guide of Offshore Oil and Gas Engineering of our country, economic analysis on the investment cost of each foundation is carried out. Finally, in accordance with the existing equipments or proposed new ones in our country, foundation structure mode of offshore wind turbine is presented which suits for the sea-conditions of Jiangsu Dafeng and Shandong Weihai. Monopole or tri-pile foundation mode is proposed and the concept design has completed.The study results of this paper can provide guidance for selection, design and construction of foundation structure of offshore wind farm in our country.