Evaluation and Stabilization of a Slope Failure at Liard Highway No. 7, km 5.9 (Case Study)
- Rita Kors-Olthof, Ed Hoeve, Bob Patrick
- September 22, 2014
- 2014 GeoRegina Conference
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Rita Kors-Olthof presents a 2014 case study, co-authored by Ed Hoeve and Bob Patrick, of the Liard Highway in the Northwest Territories, Canada. The highway was constructed in the 1980s. Upgrading and record precipitation contributed to a slope failure in 2007, and the repaired slope failed again in 2010. When slope movements were observed in 2010, Tetra Tech began an evaluation of the road.
Our team found high groundwater inflow and an underlying swale, making groundwater management a key for future stabilization. The evaluation resulted in a solution that included a longer, deeper French drain along the ditch than previously existed, counterfort drains across the highway, and a slightly flatter slope configuration. The authors also discuss site challenges and follow-up monitoring of the slope.