Conceptual design of road and bridge substructure in northern Canada with considerations for constructability and climate change

This paper presents the conceptual design process for a bridge substructure and the road surface of a permafrost-rich section along an undisclosed all-season road in Northern Canada. Vehicular access to and from numerous communities in the North relies on winter roads that traverse bodies of water subjected to deep freeze in winter months. Climate change has however caused a decrease in the reliability of many winter roads, leading to the development of all-season roads. As most all-season roads traverse regions of permafrost, the design process often requires the investigation of special technologies to mitigate permafrost disturbance. This requirement is especially important in light of the increasingly prominent impacts of climate change in the North. In addition, the remote nature of most all-season roads presents the need to consider constructability in the design of both roads and bridge structures. Hairpin thermosyphons and geotextiles were examined as potential solutions for weak and ice-rich subgrades in the road design, and socketed piles were discussed for the bridge substructure design. With the growing need for all-season roads, more papers and case studies are needed to advise practitioners on the unique challenges that are often beyond the scope of typical design guidelines. As such, this paper aims to be part of a bigger investigation that is required to ensure northern transportation networks are able to grow in the face of climate change and meet the needs of future generations.