Abstract
This paper presents the design considerations for conical steel Gravity Based Structures (GBS). Concrete GBS have been used to support hydrocarbon production facilities and offshore wind turbines in the North Sea, Sub-Arctic and Arctic regions for many years. This paper outlines the design drivers that govern the dimensions and weight of the conical steel GBS. The conical steel GBS concept has advantages and disadvantages compared with conventional concrete construction that ultimately impact the design criteria. The different design considerations to focus on include fabrication, topside installation, marine transportation, installation and the expected performance. The GBS geometry considered is a hexadecagon (16) which allows maximum topside capacity and the ability to withstand extreme weather conditions. Also, there is a challenge that has to be resolved which is to have a foundation designed for different soil properties. An ideal concept is to have a skirt design which allows the ice wall to be designed to resist the local and global ice loads. This allows optimal performance of the conical steel GBS concept.
