Bear Canyon Landslide

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The graveled road surface of Bear Canyon Road dropped several inches on a slope that had shown creep over a relatively long period of time.  Gallatin County Road and Bridge Department hired AESI to design and oversee the repair of the landslide.  AESI’s scope of work included a topographic survey, a geotechnical evaluation, preparation of bid documents, assistance with the bidding process, and periodic construction inspection.

Boreholes were drilled through the shoulder of the road to obtain soil samples for laboratory testing.  Using the soils information, laboratory testing, and topographic data, a slope stability model of the present conditions was developed in Slope/W, a limit equilibrium computer modeling program.  Various options for enhancing stability were explored in the model, including geogrids / geotextiles with terra-mesh, gabions, and other facing alternatives in combination with surface and subsurface drainage.  The alternatives with their anticipated costs and risks/rewards were presented in a geotechnical report.

Plans, specifications, and an engineer’s cost estimate were prepared for the preferred alternative.  AESI conducted the pre-bid meeting, communicated with the bidders as necessary, and made recommendations to the County with respect to bid acceptance.  AESI also conducted pre-construction meeting and provided periodic inspection during construction.