NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: physical sciences, permafrost, climate change, engineering, thaw slump

Objective(s): To develop a practical method for the mechanical and thermal design of embankments built on permafrost based on the properties of the active layer and of the permafrost as well as the loading conditions; and to develop decision-making tools to select the optimal course and the optimal embankment structure that limits the impact of the road on the environment.

Project Description: This licence has been issued for the scientific research application No.4629. The main objective is to develop a practical method for the mechanical and thermal design of embankments built on permafrost based on the properties of the active layer and of the permafrost as well as the loading conditions. The development of decision-making tools to select the optimal course and the optimal embankment structure that limits the impact of the road on the environment is also part of the research. An existing thin section of the highway embankment built on permafrost will be instrumented with thermistors, humidity gauges, stress and strain gauges. The objective is to measure the actual conditions with the natural ground. The instrumented section will be used to do in-situ testing of the embankment using heaving load trucks. The behaviour of the embankment will be recorded. Some sample from the embankment materials will be analysed in the laboratory to measure its mechanical properties. The field test results and the laboratory test results will be compared to develop damages law to help with the design of embankments build on permafrost. In-situ testing will be done during the first year at the same time of the installation of the instrumentation. In-situ testing will also be done the subsequent year at different time during the summer season to evaluate the impact of the depth of the active layer. In the field, the research team plan to to have an assistant of a local environmental worker with whom the team will exchange on the purposes and outcomes of the research and potential impacts for communities relying on critical infrastructure. The results of the research will be communicated to the transportation department of the NWT such that they can be used for future design and maintenance of embankment infrastructure. Plain language summaries will be produce such that the field operations can be explained to local workers during the operations of the second year of the project. The fieldwork for this study will be conducted from April 20, 2020 to September 18, 2020.