Monitoring of thermal and mechanical behavior of the access road to Salluit airport By : Dejan Grabundzija 15/10/2013 1. Localisation Salluit, Québec - Salluit (62° 14' N, 75° 38' O) is located north of the Ungava peninsula, in the Nunavik region - Salluit is the fourth most populated village in northern Quebec with 1347 inhabitants, after Kuujjuaq (2375) Inukjuak (1812) and Puvirnituq (1692 ) - The villages airport is an important lifeline, especially during winter months Figure 1 : Permafrost zones (Ressources naturelles Canada) 1. Localisation 2 / 17 2. Context Geology 1. Localisation 3 / 17 2. Context Structural problems of the old road • Evidence of permafrost deterioration under the road • Danger of landslides • The road was rebuilt in the summer of 2012 Figure 3 : Road deterioration summer 2012 2. Context 4 / 17 3. Mitigation • Thermal drain: - Geomembrane that allows air circulation under the embankment - Cold air enters the lower part of the embankment and the rising hotter air is evacuated at the top Figure 4: Thermal drain « Terradrain » (Jorgensen et coll., 2008) 3. Mitigation 5 / 17 3. Mitigation • Thermal drain: - Geomembrane that allows air circulation under the embankment - Cold air enters the lower part of the embankment and the rising hotter air is evacuated at the top Figure 5: Schematic of a thermal drain system (Doré et coll., 2007) 3. Mitigation 6 / 17 3. Mitigation Figure 6 : Typical cross section of the rebuilt road (Ministère des transports du Québec/Génivar) 3. Mitigation 7 / 17 3. Mitigation Thermal drain Figure 7 : Thermal drain installation 3. Mitigation 8 / 17 3. Mitigation Better drainage Figure 8 : Installation of an additional culvert 3. Mitigation 9 / 17 3. Mitigation Thermal drain Figure 7 : Thermal drain installation 2. Context 2 / 10 3. Monitoring Thermistors - 2 series of 50 vertical thermistors - 2 series of 25 horizontal thermistors - 12 thermistors inside the thermal drain geomembrane Figure 10: Thermistor distribution along the road 3. Mitigation 11 / 17 3. Monitoring Thermistors - 2 series of 50 vertical thermistors - 2 series of 25 horizontal thermistors - 12 thermistors inside the thermal drain geomembrane Figure 11 : One set of vertical thermistors 3. Mitigation 12 / 17 3. Monitoring Thermistors (initial data, summer 2012) Figure 12 : Interpolation results of the initial temperatures (October 2012) 3. Mitigation 13 / 17 3. Monitoring Inclinometers - 3 vertical inclinometers - 2 horizontal inclinometers Figure 11 : Inclinometer tube locations 3. Mitigation 14 / 17 3. Monitoring Inclinometers (results after 1 year) Figure 11 : Inclinometer tube locations 3. Mitigation 15 / 17 4. Things to come - Analysis of thermal regimes (spatial and temporal sequences) of two cross sections of the embankment (vertical thermistor series) in order to study the performance of the thermal drain - Relation between the air temperature outside and inside the thermal drain (thermistors inside the geomembrane) - Cost/benefit analysis of the thermal drain mitigation technique - Continued temperature / deformation monitoring 4. Things to come 5 / 17 Thank you to our partners and collaborators .