In Situ Monitoring and Numerical Studies on the Performance of Gentle Slopes to Preserve the Transportation Infrastructure in Northern Canada

Permafrost degradation occurs underneath the side slope due to snow accumulation, which prevents heat from being extracted from the ground in winter. This paper presents the in situ snow dynamics and thermal behavior of an airstrip in an area of continuous permafrost, in Nunavik, Quebec, Canada. The dynamic change of snow thickness around the embankment toe was measured in the field during 2014–2015. Thermistor strings were installed under the side slope and around the toe of the embankment. An empirical relationship between snowpack thickness and the freezing n-factor was proposed. The ground temperature data collected were used to calibrate a thermal conduction model, which was then used to develop the design chart for gentle slopes. The design chart was further validated using data from another experimental site at Tasiujaq airstrip in Nunavik, Canada. This work enhances the design capacity of gentle slopes to stabilize thaw-sensitive permafrost beneath the embankment shoulder.