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Tolen Bridge

Tolen Bridge
Date: 2015

To accommodate the increasing traffic demands in the City of Fort McMurray, the County of Wood Buffalo invested in the replacement of the Saline Creek Bridge. Due to changes in scheduling, the foundation piles had to be installed in spring during the fish spawning season, which caused additional environmental concerns. The surficial geology of the area consisted of stream alluvium which mainly contains sand along the river with some silt and clay over bedrock. The bedrock includes waterways formation close to the river and Fort McMurray formation with quartzose sandstone and siltstone.

Solution:

Prior to the pile installation, a sheet pile shoring wall had to be installed to allow the excavation of the abutments. The driven piles for the abutments had to be installed from the bottom of the abutment excavation, located approximately 3.50 m below street level. AGRA Foundations Limited provided an integrated solution using a crane equipped with a vibro hammer to install the sheet piles and the same crane equipped with Vertical Travel Leads, as well as a diesel hammer for the driven piles. This versatile setup allowed for considerable savings in mobilization costs and reduced the excavation volumes by allowing the piles to be driven from street level. The diesel hammer had to be properly sized to be able to transfer the energy specified for the pile installation without exceeding the maximum vibration limits that would interfere with the fish spawning.