Stabilizing avalanches

Snow fencing stabilizes snow in-place.

This project was completed under a B.C. Ministry of Transportation & Infrastructure (MoTI) “As-and-When” contract and took place on Highway 16 about 55 km west of Terrace BC. This section of the highway is situated between a rock cut slope to the north that shared the right of way with the CN Rail line to the south, resulting in limited sight and shy distances. In this area, snow avalanches regularly occur that tend to affect the highway throughout the winter, frequently resulting in delays and closures.

Thurber was retained by MoTI to provide a snow avalanche and geotechnical assessment of the area. Thurber conducted the geotechnical assessment and retained Dynamic Avalanche Consulting Ltd. as a sub-consultant to provide the snow avalanche design information.

What made this project unique is that, instead of building passive defense structures adjacent to the highway to catch the snow, the snow is stabilized in-place in the start zone to prevent the initiation of the avalanche. This installation of rows of snow avalanche fencing was a first for our client and it made the project very interesting. We used photogrammetry and drone imagery for an extension of the project for icefall catchment.