Pieces of Portland, Oregon history are being shipped down the Willamette River to find new life. The Slayden/Sundt Joint Venture has started removing massive steel truss spans from the old Sellwood Bridge, which opened in 1925, and transporting them via barge 10 miles downriver to a plant for recycling.
The joint venture team has been working with its subcontractor, an independent design firm and the owner’s design team for more than six months planning the “shoofly” removal. Before the removal could start the team had to add strengthening to the temporary piers and truss section at specific locations to counter the forces applied to the remaining sections during lowering.
The truss will be taken down in a total of nine pieces. The four main sections, measuring 200 feet apiece, will be lowered onto a barge using four 250-ton strand jacks. Each will take approximately a week to remove.
The remaining five smaller sections above each temporary bent will be hoisted onto a barge using a derrick crane. Once the shoofly truss and substructure are dismantled, a marine subcontractor will remove the 80-pipe pile from the river.
“The riveted-steel truss will be processed and sold on the open market as a scrap commodity to a steel mill or foundry for use in the production of new steel,” said Senior Project Engineer Matt Fisher. “Recycling the old bridge contributes significantly to the sustainability characteristics of this important infrastructure project.”