BAUER Foundations Canada Inc. was contracted in 2019 by Devcon Inc. to supply and install soldier piles for the debris retention structure at Exshaw Creek in Alberta. The project site was accessed through an active cement production facility. The purpose of this structure is to prevent large size boul-ders reaching a downstream bridge in the event of a flood.
BAUER Foundations Canada Inc. utilized one BAUER BG39 rotary drill rig to install the 15 x 1180mm diameter piles up to a maximum depth of 12m. Waler beams were also supplied as part of the retention system for the soldier piles.
The debris retention structure design was optimized by BAUER Foundations to allow for utilization of larger diameter bores. This facilitated the removal of larger size obstructions; and for more lenient tolerances at the bore locations. Furthermore, the design allowed for deeper but lighter beam sections than specified in the original design, resulting in cost savings for the Client.
An Alberta Transportation compliant coating was also applied to the exposed surfaces of the steel beams for corrosion protection.
The soil conditions were sand underlain by a layer of gravel, cobbles and boulders. Bedrock of 100 - 150MPa in strength was reached at between 1m and 6m below grade. The sloping bedrock combined with loose overburden consisting of cobbles and boulders made the installation of temporary casing challenging.
Despite the challenges encountered during the project, construction was com-pleted meeting specification and quality targets, to the satisfaction of the Client.