The Calf Robe Bridge in Calgary, Alberta, situated along the vital corridor of Highway 2 (Deerfoot Trail), faced a critical challenge during the upgrade of the adjacent Wastewater Treatment Plant (WWTP). The upgrade necessitated the installation of a discharge conduit downstream of the bridge. However, the alignment of the conduits intersected with the bridge abutment, demanding a bespoke stabilization solution to ensure structural integrity and prevent potential failure during excavation.
Led by GSI, a comprehensive geotechnical design was developed to address slope and abutment stability concerns. Collaborating closely with key stakeholders, GSI formulated a monitoring and controls plan, ensuring continuous oversight throughout the project. To stabilize the abutment for conduit installation, a design-build approach was adopted. This involved the installation of 280 hollow bar soil nails complemented by a 150 mm shotcrete facing. Additionally, to counter the risk posed by a potential shear band within the underlying mudstone, 118 drilled shafts were strategically backfilled with reinforced concrete.
The project employed advanced geotechnical engineering techniques and monitoring systems to safeguard the structural integrity of the Calf Robe Bridge during the installation of the WWTP discharge conduit. Daily surveys and in-situ instrumentation provided real-time data, offering stakeholders confidence in the ongoing stability of this critical infrastructure. The combination of soil nails, shotcrete facing, and reinforced concrete in the drilled shafts showcased a synergy of innovative solutions tailored to the site-specific challenges, ensuring the successful execution of the project while maintaining the uninterrupted service of the bridge.
