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TitreGeophysical surveys, permafrost conditions and infrastructure damage along the northern Yukon Alaska Highway
TéléchargerTéléchargements
AuteurOldenborger, G A; LeBlanc, A -M; Stevens, C W; Chartrand, J; Loranger, B
SourceCommission géologique du Canada, Dossier public 7875, 2015, 61 pages, https://doi.org/10.4095/296704
Année2015
ÉditeurRessources naturelles Canada
Documentdossier public
Lang.anglais
DOIhttps://doi.org/10.4095/296704
Mediaen ligne; numérique
Formatspdf
ProvinceYukon
SNRC115F; 115G; 115J; 115K
Lat/Long OENS-141.0000 -138.2344 62.6356 60.9017
Sujetspergélisol; glace fossile; interprétations géophysiques; levés géophysiques; levés de résistivité; géoradar; soulèvement par le gel; eau souterraine; méthodes analytiques; géophysique; géologie des dépôts meubles/géomorphologie
Illustrationssketch maps; photographs
ProgrammeInfrastructures terrestres, Géosciences de changements climatiques
Diffusé2015 07 29
Résumé(Sommaire disponible en anglais seulement)
The Yukon Alaska Highway is a vital transportation route connecting the resource rich Yukon to southern Canada and serving as a commercial trade and tourist route between Canada and Alaska and between the lower US and Alaska. The construction and maintenance of transportation infrastructure in permafrost regions presents challenges and costs that do not exist in other areas due to sensitivity of the engineering properties of the substrate to changes in temperature. For the Yukon Alaska Highway, road surface and embankment damage can be associated with the prevalence of warm, ice-rich permafrost. Geophysical surveys can potentially provide valuable information on permafrost and ground-ice conditions. In cooperation with Yukon Highways and Public Works, three sections of the northern Yukon Alaska Highway (23 km) have been identified for testing the usefulness of geophysical surveys for understanding permafrost degradation and assisting with highway management. Results from capacitive resistivity and ground-penetrating radar surveys were analysed and interpreted along with surficial maps, records from geotechnical borehole investigations, and surface observations of highway distress such as roughness, longitudinal cracking, embankment failures and differential settlements. Several relationships are observed. 1) Linear settlements are the most frequent and severe type of observed damage often affecting both the road surface and the embankment. 2) High degrees of road roughness tend to occur over areas mapped as till, however, identified problem areas are largely associated with fluvial and glaciofluvial map units. 3) Observed damage often occurs with high degrees of highway roughness, but high degrees of roughness are not necessarily accompanied by observable damage. 4) There is no single consistent relationship between roughness or observed damage and borehole observations of ice-rich sediment or massive ice; observed damage appears to be associated with a variety of local ground ice conditions. 5) The geophysical results help elucidate the terrain conditions and support the conclusion that multiple subsurface processes contribute to highway degradation. Several geophysical signatures are interpreted as indicative of terrain conditions involving ice-rich ground, frozen ground, thaw-susceptible sediments and shallow groundwater. Interpretation of the geophysical results is considered most reliable when done in a local context and supported by additional data such as boreholes.
Résumé(Résumé en langage clair et simple, non publié)
La route de l¿Alaska - Yukon est une voie de transport essentielle entre le Yukon et le sud du Canada et l'Alaska. La construction et l'entretien des infrastructures de transport dans les régions de pergélisol présentent des défis et des coûts qui n¿existent pas dans d'autres régions. Trois sections de la route de l¿Alaska - Yukon ont été identifiées pour tester l'utilité des levés géophysiques afin de comprendre la dégradation du pergélisol et aider à la gestion des routes. Les résultats des levés géophysiques sont analysés en en tenant compte des dépôts de surface, des forages géotechniques, et des observations de la surface de la route telles que la rugosité, la fissuration longitudinale, l¿instabilité du remblai et le tassement différentiel. Les dommages observés semblent être associés à une variété de conditions du pergélisol. Les résultats géophysiques aident à la compréhension des conditions de terrain et soutiennent la conclusion que la dégradation de la route est causée par des processus multiples impliquant des sols riches en glace, des sols gelés, l¿écoulement d¿eau souterraine et la lithologie.
GEOSCAN ID296704