By John Schneidawind
For Ken Butler, senior vice president and chief bridge engineer at AECOM, restoring the nearly 90-year-old Arlington Memorial Bridge was like restoring a priceless antique.
The National Park Service-owned span was so deteriorated it ranked among more than 47,000 “structurally deficient” U.S. bridges, as determined by the Federal Highway Administration (FHWA). Because it is a major commuting route between Northern Virginia and the Nation’s Capital, the $227 million rehabilitation required two phases to keep traffic moving in both directions.
“The aesthetic and architectural features are so unique and complex,” says Butler, who specializes in complex bridges. “We had to make sure that the refurbishing of all the granite, the railings, the lampposts was meticulously documented, refurbished and put back in place in the exact same spot.”
Butler and Don Arant, project manager for design-build contractor Kiewit Construction Co., approached the project with loving care and smart, modern methods. Structural solutions were developed through 3D finite element software, which predicts how a product reacts to forces such as vibration, heat, fluid flow, and other physical effects to determine if it will break, wear out or meet the design challenges.
The bridge’s floor beams were cut in half lengthwise, which weakened the structure, and required temporary supports along the roadway centerline under the bridge. Cutting these beams in half also would impact the bridge’s balance.
Decades of salt used to melt winter ice and snow had rusted the bridge’s steel and concrete supports. A drawbridge function was eliminated since ships no longer sail north of the bridge. Crews installed fixed steel beams over the drawbridge space and more than 450 precast concrete panels. Workers repaired or replaced the bridge’s foundations, concrete supports, deck, and sidewalks.
The biggest challenge was how to remove—intact—the ornate architectural fascia and decorative balustrades that give the bridge its character. The fascia was comprised of a steel supporting truss and a complex array of light gage members and steel panels to create the ornamental appearance. That made it heavy to remove, restore, and re-attach to the fascia truss of the replacement bridge.
Kiewit worked with FHWA engineers to develop a jack-up barge that transported many of the bridge’s prefabricated components from a riverside workplace on the Virginia shore. Kiewit built a custom cradle and picked the fascia off as an entire unit, lowered it into the scaffolded cradle onto a barge, floated it to shore, and restored it there.
“It was a very elaborate façade with a lot of three-dimensional texture to it, with lots of monuments, buttons and stars,” says Kiewit’s Arant. “The beauty of that was that we didn’t have to ship it off site,” he said. ARTBA members Brayman, High Steel, PennStress, Vulcan, and Wagman also were part of the 40-member team of contractors, designers, consultants, and suppliers on the project. The project was completed Dec. 4, 2020.
This story appeared in the January/February issue of Transportation Builder. John Schneidawind is ARTBA’s vice president of public affairs. Photo: Arlington Memorial Bridge work in September 2019. NPS photo by Jarob Ortiz.