Abstract Manager

The Canada Drive-America Avenue Underpass is a newly completed vehicular and multi-use pedestrian bridge located in Vaughan, Ontario that enhances the city’s transportation network and connects communities across the twelve-lane Highway 400. The project presented many technical challenges, including close collaboration with local regulatory authorities and fabricators to modify the standard NU1400 girder to include post-tensioning – a first in Ontario.

The CDAA Overpass is a two span, slab on girder bridge consisting of equal 40.5 metre spans with seven precast NU1400 girder lines at a spacing of 2.050 metres. Since the bridge ties into existing intersections on each side of Highway 400, there was a need to design the superstructure to be as slender as possible to keep the approach slopes acceptably gradual. While steel box girders would be a natural response to this constraint, schedule and cost considerations favoured a precast concrete solution. The addition of post-tensioning allowed the slenderness of the precast girder alternative to match that of a steel box superstructure. Extensive collaboration was required to ensure the design complied with all stakeholder requirements, and with local precast fabricators to adapt their processes and formwork to the addition of post-tensioning.

This paper presents the design and construction of the bridge, which provides an economical connection for the City of Vaughan, while extending the capabilities of NU Girders in Ontario.