Innovative ‘Shoofly’ Approach Helps Sundt Team Win Oregon Bridge Project

 |  Laboratories & Healthcare
Sellwood Bridge rendering
Designed as an open steel deck arch structure, the new Sellwood Bridge will complement its surroundings while providing ample space for all modes of travel.

When you combine Sundt‘s size and proven ability to be innovative with the knowledge and experience of a local contractor, you get a project like the $160 million reconstruction of the Sellwood Bridge in Portland, Ore. Sundt and joint venture partner Slayden Construction used Building Information Modeling (BIM) and a sophisticated video presentation to develop and propose a faster, safer and less expensive method for reconstructing the aging bridge than was originally called for in the project’s Environmental Impact Statement. The approach will shorten the project schedule by approximately one year and reduce the cost to the owner, Multnomah County, by $5 to $10 million.

The 86-year-old Sellwood Bridge stretches 2,000 feet across the Willamette River. Rather than rebuilding it in sections and shifting traffic back and forth between the old structure and newly completed segments, the team will create a “shoofly” (detour) bridge to keep traffic flowing throughout the project. The approach involves lifting the old bridge deck and truss with hydraulic jacks and moving it to one side, then placing it on a set of temporary piers and connecting it to temporary approach spans so that traffic can continue to use it while the new bridge is constructed.

What are the benefits? Creating a detour bridge is safer for construction crews and the public because it frees up the existing alignment for workers and keeps traffic out of the construction zone. By eliminating the need for complicated traffic phasing, it also shortens the project duration and therefore the overall cost. Another benefit is that it allows for a sleeker bridge design with fewer redundant features and fewer in-water impacts, which is better for the river’s ecosystem.

The new Sellwood Bridge will be complete and efficiently transporting motorists, bicyclists and pedestrians across the Willamette River in 2015.