Innovation, Sustainability Lead to Successful Completion of Sellwood Bridge
PORTLAND, OR After five years of work, the Slayden/Sundt Joint Venture recently completed the new Sellwood Bridge for Multnomah County, Oregon.
The bridge replaces the deteriorating, 92-year-old original Sellwood Bridge, the community's only crossing over the Willamette River for 12 miles. Sellwood Bridge is the state's busiest bridge and was an iconic piece of architecture.
The new bridge, designed by T.Y. Lin International, is an open-spandrel steel deck arch structure that complements the immediate surroundings. The bridge features two vehicle lanes in each direction on the west end, which narrow to one lane in each direction on the east end. The bridge also has two six-foot-wide bike lanes and two 12-foot-wide sidewalks.
"This is a standout project for the people and the community," said Ted Aadland, Sundt's Area Manager.
The project team applied a variety of innovative approaches throughout the construction process. To allow traffic to continue flowing during construction, the Slayden/Sundt team used a "shoofly," or detour bridge. The team lifted the old bridge deck and truss with hydraulic jacks and moved it to one side, placing it on a set of temporary support piers.
The shoofly method minimized bridge closures to avoid negatively affecting the thousands of drivers who use the bridge each day. The shoofly cut roadway closures to less than the 30 days called for in the contract, saved $5 million and took a year off the entire project schedule.
"The idea of moving the shoofly was definitely thinking outside the box," said Aadland. "This was one of the longest bridge sections ever to be moved. The idea saved money on the project and reduced road closure days."
Portland will be able to enjoy the new Sellwood Bridge for many years to come. Constructed out of weathering steel, the material rusts and oxidizes and protects itself. Common for steel bridges constructed today, the weathering steel reduces the need for constant re-painting of the bridge.
Sustainability measures were also an important element to the project. When Multnomah County asked the project team to clear a trail on the east side of the river, the team used a herd of 60 goats to chew brush on the site. The goats reduced the project's energy use by eliminating the need for equipment to clear the brush, and the team reduced the environmental impact of disposing the cleared brush. The goats will return in the spring for additional clearing.
As Multnomah County residents enjoy their new bridge, they will be able to remember a piece of the original one. The Sundt/Slayden Joint Venture donated a segment of the old bridge to a local neighborhood for a permanent display. A piece of the historic bridge railing now sits in front of the SMILE Station at S.E. 13th and Tenino in Sellwood.