Initial Results from Temperature Monitoring in a Culvert under Winter Conditions in Permafrost

ABSTRACT: Culverts installed across road embankments maintain natural drainage conditions and minimize hydrological impacts. In northern applications where permafrost is present, culverts are installed during winter, such as the case of the newly-opened Inuvik-Tuktoyaktuk Highway (ITH) in the Northwest Territories. This means the fill material is placed and compacted in frozen condition. Culverts affect the thermal stability of road embankments. They act as heat conduits during summer, but depending on its diameter can trap heat during winter. Thawing of soil around and below the culvert will lead to differential settlements and longitudinal cracks at the road surface and embankment slopes. In order to study the effects of culverts on the thermal behaviour of surrounding soil, a 5-noded thermistor string was installed inside an 800 mm diameter culvert along its length. Temperature readings along the culvert from the time of installation and during the winter months are presented in this paper.