Mechanics of Iceberg and Sea Ice Failure in Offshore Engineering Applications

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Canada has a wealth of natural resources, including vast potential mineral and hydrocarbon reserves in arctic and subarctic regions. Canada's Northern Strategy also serves as a vital part of national policy in which promoting economic development, protecting the environment and assertion of sovereignty are important objectives. The assertion of sovereignty will necessitate a fleet of ice-breaking vessels capable of year-round operations in the Arctic. The research proposed herein will promote greater understanding of extreme ice loads and associated failure processes and is highly relevant to future construction of such vessels. Moreover, the development of Canada's north implies increased shipping activity, oil and gas exploration, as well as northern infrastructure projects. The presence of sea ice and glacial ice is a dominant consideration in the safe, economic design of ships and structures for such developments. For regions such as the Labrador Sea and eastern Canadian Arctic (e.g. Baffin Bay), which are highly prospective for offshore oil and mineral developments, the presence of embedded massive ice features (e.g. multi-year ridges, icebergs and ice island fragments) frozen into the sea ice cover presents designers with significant new challenges. While established methods and best practices are available for either operations in sea ice or for operations in regions with icebergs in open water, new approaches are needed to improve the modelling of interactions with embedded massive ice features in sea ice.***From a design perspective, extreme ice loads associated with ice crushing failure is an essential consideration. Compressive failure of ice is a complex process, and the localization of contact into high pressure zones (hpzs) during an ice-structure interaction is an important aspect. Avoiding unwanted structural vibrations during dynamic ice crushing failure is also highly relevant. Fracture processes, as well as pressure softening due to microstructural modification, play an important role in compressive ice failure. Large-scale fractures associated with the failure and break-out of massive ice features also need to be modeled and randomness associated with these fractures necessitates a probabilistic approach. Many questions remain unanswered in this area. The overall goal of the program is to reduce uncertainty in the knowledge of ice failure processes and improve methods used in the design of structures for interactions with embedded massive ice features frozen in sea ice. Ice failure and interface bond properties between dissimilar ice types will be explored through an innovative experimental and theoretical modeling program. Focus is placed on understanding fundamental aspects of interaction mechanics and ice fracture processes.The training of HQP to build the next generation of Canadian Arctic experts is another highly important goal of this program.***