Project of the Year: Historic Category
Upper Perry Arch Bridge Repairs
La Grande, Oregon
Submitted by The Euclid Chemical Company
Oregon Department of Transportation
Wildish Standard Paving
The Upper Perry Arch Bridge spans the Grande Ronde River and the Union Pacific Railroad in Perry, OR. This bridge has special historic significance because it was one of the earliest arch bridges designed by Conde B. McCullough—Oregon’s first state bridge engineer—famous for his arch bridges along the Oregon coast.
In the 1970s, the Oregon Department of Transportation recognized that a significant number of its historic bridges were deteriorating in ways conventional maintenance could not control. A new engineering unit was assigned to evaluate the bridges most at risk and develop techniques for restoration. The Upper Perry Arch Bridge was one of the bridges identified for evaluation. The bridge was in very poor condition—the deck was riddled with cracks and spalls, the rails were crumbling, and there were exposed reinforcing bars in numerous locations. Weight restrictions were imposed, allowing only passenger-car traffic to cross.
After the evaluation, it was decided to restore the bridge, not demolish it. Repair work included epoxy crack injection, cast-in-place concrete repair, form-and-pour repairs with a prepackaged repair mortar, the application of a low-modulus epoxy deck sealer, and waterproofing coating of vertical surfaces. Repairs were made to dentils, corbels, sidewalk brackets, decorative concrete bridge rails, fascia beams, post caps, and large arches.
Various concrete placement methods were used, including form and pour, pressure grouting, and gravity feeding. At times during construction, temperatures dropped to -15°F
(-26°C), which required the use of heated, tented areas.
The restoration met the goal of recreating the original look of the structure sought by McCullough 90 years ago while protecting the bridge from deterioration for another 50 years. Despite the challenges, the arch was successfully rehabilitated ahead of the revised schedule and within
the revised budget.