Vehicular

Bridge

Three pairs of 10 ¾” thick curved sections of glue-laminated southern yellow pine create the bridge’s 75’ long by 11’ wide deck. To maintain the curvature of the road that serves it, we formed the panels as “glulam” arches that were then laid on their sides. With the lamination laid up in this axis, each panel acted as a monolithic slab, in which each lamination transfers and spreads the heavy wheel loads of construction vehicles laterally to adjacent laminations through the continuous structural glue joints that bind them together.

We determined 10 ¾" depth as the minimum section modulus required for the member to resist the axial load of the 10 ton vehicles that were to use it. Our glue laminator’s limit for the width of a single lay-up was 60”. Two of these planks, laid side by side, provided sufficient width for a single traffic lane and reiterated the wheel tracks of the small access road that serves the bridge. Two bolt-laminated wooden rails, harnessed to stone anchors at each abutment and clipped to a series of galvanized steel supports, form wheel curbs that trace the deck’s curved edge.