Climate Control Triaxial System for Strength Assessment of Frozen and Partially Frozen Soils

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Nearly a quarter of the northern hemisphere, including half of Canada's landmass, is underlain by permafrost. Essentially, permafrost is ground that remains perennially frozen for at least two years below zero degrees centigrade. Rises in temperature due to climate change have detrimental impacts on the strength and integrity of permafrost. The ramifications of this warming include increasing instability of shallow slopes and deformation of near-surface infrastructures, such as pipelines, and will impact landscape design in mine reclamation framework. Warming allows ice in the pore space to change phase to water, and this water can result in increases in internal pore water pressures in the partially frozen material. The proposed triaxial system will enable us to measure pore pressure increase with controlled warming and therefore quantify the subsequent strength reduction relative to temperature profiles. The requested state-of-the-art environmental triaxial testing system is capable of testing frozen and partially frozen soil under controlled temperature conditions to monitor the pore pressure transitional changes as frozen soil thaws. This system will allow us to compile a unique experimental database to develop and calibrate numerical models capable of predicting the change in the strength of frozen soils as it thaws. Although triaxial tests are routinely used in geotechnical engineering to measure strength of soils, they are rarely utilized to understand effective stresses in frozen and partially frozen soils. By acquiring this system, our research group would be at the forefront of making significant and fundamental contributions to Canada's northern development in three key research areas with strong support: mining waste management, construction, and railway industries. Furthermore, it will help create an edge in our HQP training, providing them with a unique skillset to place them in impactful future roles.