UW GIGSS & ASCE GI Seattle - DFI Traveling Lecture

DFI Traveling Lecturer: Rick Deschamps

Topic: Emergency Repair of Fountain Slide to Maintainer CN Rail Service

Abstract: Fountain Slide, located approximately 16 km northwest of Lillooet, British Columbia, is a relic landslide that has been active since the 1970s. The slide began impacting train operations and in 2004 the Canadian National Railway Company (CN) undertook measures to stabilize the railbed during the following 11 years including track realignment, shotcrete tie back wall and a soldier pile and lagging wall with three levels of anchors. In mid-2014 the slide retrogressed above the tracks and movement increased to about 7 mm per day, leading to extreme distortion of the earth retention system and frequent realignment of the tracks. In the summer of 2016, a design build system of micropiles and anchors was implemented to stabilize the slide. The approach was used because of limited access for large equipment and the need for a ductile stabilization system because of the ongoing movements during construction. Movements were as high as 20 mm/day during construction but continued to decrease during and after construction and the tracks were stabilized. The presentation discusses the design considerations and final approach implemented, construction activities, and deformation monitoring during and post construction.