Structural Stability of Highway Embankments in Canada’s North

The completion of the Inuvik to Tuktoyaktuk Highway (ITH) in the Northwest Territories has been a long standing goal of the residents of town of Inuvik, the Hamlet of Tuktoyaktuk, and the Inuvialuit Settlement Region. This highway will be an all-weather transportation link and will complete Canada’s road network from the Pacific, Atlantic, to Arctic coasts. Road access to the north is essential for Canada as it addresses the goals of northern economic development and strengthening of Canadian sovereignty in the Arctic. The northern environment and the increasing effects of climate warming, however, pose serious challenges in the construction and serviceability of highway embankments in Canada’s North. The ITH is located within the Arctic Circle and founded on permafrost (frozen ground). Soils are almost always stronger when frozen than thawed. The stability of the infrastructure is dependent on maintaining its frozen state. Typical construction methods employed when no frozen ground is present cannot be used for such applications. Permafrost degradation and thawing of ice wedges underneath road embankments can result to significant settlements and potentially affect the integrity and performance of the embankment. Construction is done only during the winter season for ease in moving fill materials and to minimize environmental impacts.