North End Park Pedestrian Bridge

The North End Park Pedestrian Bridge is designed as an extremely shallow arch that utilizes the natural curvature of the timber and concrete to transfer loads through compression (arching action). The bridge engages the concrete topping and timber in composite action, facilitating the slender profile desired by the owner and architecture team.

The timber profile consists of very narrow glulam members with gaps at either end of the bridge. The gaps taper to nothing at mid span, giving the bridge an hourglass-like shape in plan. In elevation, the glulam gradually tapers from a 20” depth to 8 ¼” deep at mid span, resulting in an extremely slender structure. The glulam supports a pre-cast concrete deck with a cast-in-place topping slab.

The ends of the bridge are longitudinally ‘locked in’ with a jacking mechanism that allows the arch thrust force to be engaged for the deadload while accommodating for construction tolerances in the concrete substructure. Meanwhile, a spring mechanism comprised of steel plates engaged with jacking bolts accommodates potential long-term displacements of the concrete structure.