Acceleration-oriented design optimization of ice-resistant jacket platforms in the Bohai Gulf

Abstract

The Bohai Gulf in China is home to a marginal oil field that freezes during winters. The two key aims of the designers are to design both economical and ice-resistant offshore oil platforms. Originally, the jacket platforms were designed to withstand the extreme static ice force. However, severe ice-induced vibrations have been observed during the winters. Researchers have systematically studied the ice-induced vibration and the related approach to ice-resistant jacket platform design. As a part of these studies, this paper proposed an acceleration-oriented design optimization of ice-resistant jacket platforms in the Bohai Gulf. This approach focused on the dynamic performance of the jacket platforms in terms of the deck acceleration and employed the structural optimization technique to achieve an economical and rational design. The proposed design optimization accounts for the uncertainty of the ice environments and the variability of the ice-resistant structure during the optimization procedure by introducing a failure probability-based approach. This is used to determine the short-term dynamic ice case for dynamic analysis of the ice-resistant jacket platform. Finally, an example of a real ice-resistant jacket platform demonstrates the applicability and feasibility of the proposed method. This can help designers achieve a design that satisfies dynamic performance criteria while maintaining an acceptable weight.