Situation
The original Sellwood Bridge, built in 1925, was the first fixed-span bridge on the lower Willamette River and a pioneer in area bridge technology. Originally intended for the local community, it became a primary connector for eastside residents headed for I-5 and Washington County. More than 30,000 vehicles crossed the bridge daily, severely constraining its capacity and original purpose. Construction of a replacement bridge began in 2011.
Solution
GBI was responsible for excavation, embankment and support for the bridge’s 18 retaining walls. This entailed 100,000 cubic yards of excavation, 40,000 cubic yards of embankment, and 60,000 tons of rock plating and drill pads.
Additionally, we removed more than 40,000 tons of contaminated soil, installed 14,250 square feet of anchored wire mesh slope protection—the site sits in the middle of a bowl formed by an ancient landslide—and constructed 4,500 linear feet of new highway and ramps.
The project had numerous phases to minimize impact to the traveling public throughout the three-year construction schedule.
Notable
The project used 20% minority, 20% trade apprentice, and 14% female workforce.
The new bridge was designed to be operational with minor repairable damage through a 500-year earthquake and to withstand a 1000-year event without collapse.
