Effect of climate-driven loading events on slope stability

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Over the last century, landslides in Canada are estimated to have cost over $9.5 billion CAD in both direct and in-direct costs, and have resulted in over 600 fatalities. As Canada continues to experience increased precipitation and temperatures, the socio-economic cost will continue to rise as slopes and embankments which were previously stable face increasing risk of failure.  Efforts to understand and mitigate the impact of climate change on slope stability is critical. Specifically, Canadian engineering ‘best practices’ for slope stability need to be addressed for a changing climate in order reduce the risks associated with climate-driven landslides. The overall goal of this research program is to understand how climate change will trigger landslides in otherwise stable slopes, and to use that knowledge to improve landslide risk assessment techniques. In this research program, two themes will investigate this challenging problem of how climate change impacts slope stability. The first theme will focus on understanding how climate change triggers landslides, concentrating on degrading permafrost and the role of soil thickness. To accomplish this, twenty geotechnical centrifuge landslide experiments will be conducted, as well as field investigations in the Northwest Territories. The scientific findings, acquired through these physical model experiments and site-investigations will have a transformative effect on the development of climate-driven landslide mitigation and slope stabilization techniques in urban and cold regions in Canada, and will provide the critical physical data needed to verify developed numerical prediction and propagation models. The second research theme will focus on risk assessment techniques, first with the development of a sensor that measures large suction stresses in the field. This will enable long-term slope stability monitoring for high-risk slopes exposed to climate changes, and provide practitioners with a cost-effective monitoring device that increases the warning time prior to a landslide. In addition, improvement to landslide susceptibility and hazard mapping techniques will be developed, targeted at expanding mapping techniques to include the impact and associated risks of climate change in urban and northern regions. Six graduate and five undergraduate students will be trained in this research program and will gain expertise in technical, scientific, research and soft skills. The developed knowledge gained by students can be applied in a wide variety of applications, including geotechnical infrastructure design, geohazard investigations, and landslide risk assessment. In the long term, the research will benefit Canada by reducing the socio-economic costs and risks associated with landslides, and will improve the safety and stability of our natural and engineered slopes that are impacted by climate change.