Basic Design of Jacket Substructures for the South-West Offshore Wind Farm Project in Korea

摘要

Four jacket substructures are designed for the four different offshore wind turbines (3.0MW, 5.0MW, 5.5MW, 7.0MW), which are under development in Korea. Transition pieces connecting towers and substructures are also designed in this basic design. In order to confirm safety of the substructures and transition pieces, dynamic characteristics, member stress level, maximum lateral displacement, geotechnical resistance, and pile driving is investigated in this project. Slop of the jacket leg is adjusted to avoid a resonance between the upper part and the lower part. Three different jacket brace layouts are considered in the structural designing part. Unfortunately, fatigue check has not been executed in this basic design. Usually, jacket substructures can be installed by either pre-piling method or post-piling method. Considering ocean environmental condition of the South-West Offshore Wind Farm project site and previous experience of the Korean construction engineers, post-piling method is selected for the offshore installation of the designed jacket substructures. Combination of installation vessel and equipment is also considered in this basic design.