Partial Stabilization of an Active Slide Area Utilizing Soil Mixed Shear Keys installed Using Cutter Soil Mixing: Results of a Test Section

摘要

The Fountain Slide is located on Highway 99, British Colombia, Canada, approximately 17 km east of the town of Lillooet. The slide, which incorporates about 750,000 m~3 of material, is part of an ancient earth flow which has been active for decades, with recorded movements between 2006 and 2009 in the order of 4 m. As a result of the large movement, the British Columbia Ministry of Transportation and Infrastructure converted approximately 300 m of the paved road surface to gravel so that it could be better maintained, and commenced investigation of suitable alternatives to mitigate on-going movement. Following their assessment of the engineering parameters of the slide, and a review of potential stabilization options, the Ministry elected to design and install a test stabilization section comprising a series of soil-cement shear keys installed using Cutter Soil Mixing. This paper presents background data on the slide, an overview of the conceptual design rationale used in the selection of parameters for the test section, the challenges and experiences gained during installation of the test shear keys, as well as the results of both the monitoring of the slope and the short and longer-term strength data accumulated for the soil-cement shear keys from both wet-grab and cored sampling programs.