Evaluation of Ice Loads acting on Spray Ice Islands

The magnitude of ice loads imposed onto a structure located in land fast ice, such as an ice island, is usually controlled by the failure mechanism of the ice at the interface with the structure – crushing of the ice sheet or passive edge failure of the ice island. These ice loads are resisted by a grounded ice island through sliding resistance along the seafloor and internal shear within the island. Methods of assessing ice loads imposed on ice islands are addressed, focusing on alternative mechanisms which may result in lower failure loads than using traditional analysis. A comparison is made between the requirements of various codes of practice and guidance documents available to the industry, including the recently updated CSA S471-04. Potential methods of reducing ice loads using monitoring of ice conditions and active operational management are also reviewed and discussed, as well as potential areas for future research and development.