Numerical Simulation of Extreme Ice Loads on Complex Pile Legs of Offshore Substation Structures

Abstract

The sea ice failure mode and ice force amplitude depend on the structural form at the point of interaction, but the impacts of ice load when interacting with marine engineering structures with additional attachments are not yet clear. This study conducts numerical simulations using the discrete element method to investigate the interaction between sea ice and cable pipes attached to offshore substation structures. Various operating conditions such as ice velocity, ice thickness, and ice attack angle are selected to simulate the interaction between sea ice and such structures, clarifying the variations in the sea ice failure mode and ice force amplitude. The results indicate that crushing failure mainly occurs when sea ice interacts with such structures, and the presence of cable pipes does not alter the sea ice failure mode at the legs of offshore substation structures. The preliminary action of sea ice with cable pipes effectively reduces the ice load on the structure, and the minimum ice force amplitude occurs at an ice attack angle of 90°, with the ice force amplitude increasing with the ice thickness but showing no clear correlation with the ice velocity. The findings of this study provide a reference for the ice-resistant design of offshore substation structures in cold regions.