A Perspective on Stabilizing Landslides and Slopes in Challenging Terrain Using Rigid Structural Elements

In challenging geologic and topographic conditions, traditional earthworks and drainage measures may be unfeasible, impractical, or insufficient, and rigid structural elements are used to stabilize existing landslides and to enhance the stability of slopes for transportation projects. Rigid elements commonly used for slope stabilization include drilled shafts or driven piles for passive slope support, retaining structures, and post-tensioned ground anchors for active support. A perspective is provided on these types of rigid inclusions using experiences from landslide and slope stabilization projects in the challenging, glaciated, and mountainous geography of western Canada. The perspective includes key considerations in the selection of the most effective structural support elements and integrating structural support with traditional earthworks and drainage measures for the optimal overall geotechnical approach to design. Geotechnical and structural monitoring results from completed landslide stabilization projects are described to illustrate the effectiveness of the rigid elements during and after construction. Important learnings from construction are provided, and results of geotechnical instrumentation are evaluated and interpreted. Based on experiences from several geotechnical designers and projects, the authors provide a summary of the site conditions that influence the selection of rigid inclusions and structural support for the stabilization of steep slopes.