Review of Standards for Ice Forces on Port Structures

Port structures in cold regions generally take the form of large caisson structures or piled structures. There are limited standards for such structures, so the following standards for highway bridges and offshore structures were assessed for application in specifying ice forces on port structures; CSA-S6 Canadian Highway Bridge Design Code, ISO 19906 Arctic offshore structures, CSA-S471 General requirements, design criteria, the environment, and loads, API Recommended Practice 2N Planning, Designing, and Constructing Structures and Pipelines for Arctic Conditions (1995), and Russia's SNiP 2.06.04-82* Loads and Effects on Hydrotechnical Structures. The ice condition considered was level ice 0.2 to 2 m thick. Three typical structures were evaluated; 1 m diameter pile, 4 m diameter structure and a 50 m wide structure. CSA S6 was found to be best suited for small pile structures (~1 m dia.). For slightly larger structures (~4 m dia.), CSA S6 was the best choice, but ISO 19906 and CSA S471 could be used for ice thickness greater than 1.2 m. Finally, for wide structures CSA S471 was most suitable, but ISO 19906 or API RP 2N could be used for ice thickness greater than 0.6 m and up to 2 m.