The Kingsway pedestrian bridge spans across one of Burnaby’s main thoroughfares. The design team opted for a simple and elegant single-arch span from which the walkway would be suspended on steel tension rods.
In the interests of economy, buttresses were avoided and instead the arch is tied using the walkway itself to resist the outward thrust. The bridge was to be partially covered, which offered the opportunity of introducing wood into the design.
The arch has steel haunches where the structure is exposed to the elements, and these transition to glue-laminated timber (glulam) where protection from the weather is provided by the roof. To achieve a lightness of appearance and to minimize the structural depth, six shallow arches are used rather than a single deep arch on either side. The outermost members are made up of two narrower thick glulam components to combat bi-axial stress created by pinching the arches together at the crown.
The entire wood portion of the bridge, including the tapering roof panels, was prefabricated in a parking lot adjacent to the site. When lowered into place, the two sections of the exterior arches (as well as the wider intermediate ones) were squeezed together and held in place with tension rods. Prefabricated roof panels were then dropped into place.
The glulam arches support HSS beams that project slightly beyond the edges of the roof. Steel rods attached to these beams support the precast concrete walkway. These sections, together with internal wood blocking between the glulam, serve to transfer some of the vertical loads away from the outermost arches.