Written by Pamplin Media Group –
January 19, 2013.
About 12 hours after it started inching its way into its new location Saturday, the 87-year-old Sellwood Bridge’s 1,100-foot truss span was set up in its temporary place to make way for construction of a new bridge.
By about 9:30 p.m. Jan. 19, crews with Pacific Northwest contractor Omega Morgan had set the span in place. Demolition begins early Sunday on the bridge’s westside approach. The temporary “old” bridge should be reopened to the public on Thursday, slightly skewed — about 33 feet to the north at the east end and about 66 feet at the west end — from the former bridge’s location.
At the new location, the truss will be supported on five temporary steel piers.
The contractor continues working around the clock after the move is completed to connect the truss span to the west and east approaches to the detour bridge.
An independent engineering inspection of the truss span begins next week, to confirm that the detour bridge is safe to open to traffic.
Largest bridge section moved
Omega Morgan, which has an office in Hillsboro, began sliding the bridge truss north to its temporary location at about 8 a.m. Saturday. The move was part of the $307.5 million replacement project by general contractor Slayden-Sundt Joint Venture. It is expected to save about $5 million to $10 million in construction costs and cut about a year off the project schedule.
The new Sellwood Bridge opens in the summer 2015.
The 3,400-ton truss span was one of the longest bridge parts ever moved. The age and shape of the truss combined with the curved path of the move make it a complex undertaking.
The aging and crumbling Sellwood Bridge is about 1,972 feet long, 75 feet high and about 28 feet wide. It is among the state’s busiest bridges, with 30,000 vehicle crossings each day.
Omega Morgan’s Chief Engineer Ralph DiCaprio devised a strategy to move the bridge in one piece by sliding it on skid gear to the north of the existing bridge and then mount it on new piers that have been built in the river.
The “old” bridge becomes a “shoofly,” or detour, while construction begins on the new bridge.View the original article.