Soil Nailing & Mesh for Permanent Slope Retention

Project Description

The project consisted of the replacement of a 100-year old steel bridge connecting residential and downtown Edmonton. Permanent slope protection was designed for the existing hillside adjacent to the bridge to facilitate a new Single span bridge and the increase hillside loading for the new bridge abutments.

Soil nails were used to provide global stability of these embankments. To prevent localized sliding, heavy wire mesh was connected to the soil nails. Topsoil fill and landscaping were then used to hide the mesh and create a root matrix at the face of the slope retention. Due to the weak nature of the surface soils, hollow threaded bars were used so that the soil nails could be installed without the use of casing.

This allowed the use of air track tethered to a D6 dozer and an excavator mounted drilling specially sourced for this project for the challenges of the steepness of the embankment. A majority of the soil nailing work outside the footprint of the existing bridge was completed ahead of the demolition in order to minimize schedule impacts. After the bridge was taken down, the remainder of the soil nails were installed then all of the mesh. The slope retention work was completed on time and under budget.