Alternative mitigation strategies for landslides impacting pipelines: use of compliant materials to lower tractive forces in moving ground

Dr. Alex Baumgard, BGC Engineering, Inc.

When constructing infrastructure, landslides are good things to avoid. However, sometimes one can’t – either the infrastructure is already in place or there are other constraints that prevent going around them. This leaves engineers to manage landslides. Typically, landslides are managed by either stopping the driving forces or stabilised by mechanical means such as anchorages or buttresses. However, an alternative management strategy exists, wherein the infrastructure is designed to work with the landslide movement. The use of compliant backfill materials are now being implemented on some real-world examples in an attempt to reduce traction forces from landslides, thereby allowing them to move past the pipeline rather than apply load and stress. This presentation will outline some of the background soil-structure interaction theory, current research being completed at Queen’s University in Canada, and provide examples of how compliant materials and construction techniques can be used to accommodate a moving landslide including where it has been applied on the Trans Mountain Expansion Pipeline.