Located in Fort McMurray, Alberta, this new vehicle and pedestrian bridge structure provide a key crossing over the Hangingstone River. The cast-in-place posttension concrete pedestrian bridge is supported by a contoured single steel arch connected to two concrete cone bases on each end of the walkway.
The 1.2 meter diameter prefabricated steel arch is a key feature and critical component of the project. Due to its complex geometry, the project team carefully coordinated the fabrication, onsite construction, and connection details using Building Information Modeling (BIM) technology to mitigate risk associated with the lift of the steel arch. BIM and virtual construction (VC) processes and tools were used to create a digital model of the concrete base and associated steel arch. This included 3D scanning, 3D printing, and robotic total station surveying. The effective implementation of BIM and VC ensured both the steel arch and the concrete cone bases were completely compatible, allowing the arch’s base plate to line up precisely with the steel anchor bolt settings embedded in two concrete cone bases.
Strong collaboration with the consultant and steel subcontractor ensured the final model matched the consultant’s design intent and effectively communicated the complexity of the geometry to all involved in the project. This collaboration reduced the lift time from 20 hours, which was initially budgeted in the schedule, to eight hours.
The use of BIM and VC tools allowed the project team to implement a virtual quality process that added value to the survey, formwork construction, shop drawing development, and rebar detailing and installation. The use of BIM and VC also supported project planning and execution through the early identification and mitigation of risk on a complex project.