Abstract Manager

The construction in the Arctic is one of the most challenging engineering problems. Northern communities rely on transportation and connections to other regions for survival, as well as for access to essential health and life-sustaining products. Road construction on permafrost typically involves using thick granular embankments to provide thermal and mechanical protection for the natural subgrade soil. The increased effects of climate change, in combination with the possible construction of thinner embankments due to limited access to high-quality natural resources, imply that unpaved roads in the North are likely to experience an increase in active layer thickness and permafrost degradation over time underneath the transportation infrastructures. This is likely to cause a more significant seasonal mechanical weakening in summertime. In order to take into account those evolving structural conditions, a comprehensive structural design method is required to take into account the seasonal variability of the pavement response and behaviour. This study was developed around a test section on the Inuvik-Tuktoyaktuk Highway (ITH) by embedding several thermal, moisture, pressure cell and deformation sensors at different depths and distances in one location. The instrumentation was done in 2019, and the data was recorded until 2024 for detailed analysis. Six field measurement campaigns (2022 and 2024) were organized with the goal of recording the properties of embankment and soil at varying thaw front positions. A loaded dump truck was used during each campaign to run over the road for data recording under controlled conditions. The truck was driven at three different speeds (5 km/hr, 15 km/hr, and 25 km/hr) on the centerline of the sensors. Additionally, other testing such as light weight deflectometer (LWD) and dynamic cone penetration (DCP) was conducted to assess pavement system layers properties. The result of this research indicates the influence of thermal properties on the mechanical response of the soil, which will identify the key factors that affect road performance. The seasonal behaviour and understanding of its impact will ultimately result in improved design methods and durable road infrastructure in permafrost regions.