Finding solutions to complex issues is what the Atkinson Construction team does best. So, when the Washington State Department of Transportation (WSDOT) identified a damaged section of an outside support beam on the SR 99 Aurora Avenue Bridge in Seattle that needed immediate repair last fall, Atkinson was the first company that came to mind.
Following years of corrosion and traffic pressure, a portion of the right-hand, southbound lane of the bridge had sunk by about half an inch. WSDOT determined that the damaged section of the stringer, a steel piece that runs lengthwise under a bridge deck and is riveted to beams with steel plates to carry the weight of the deck, would need to be rebuilt and strengthened.
Within 48 hours of assembling the project team which included Apex Steel and Purcell Painting and Coatings, Atkinson designed and erected a temporary scaffold that provided access to the repair area. Providing access to the damaged stringer was especially challenging as it was located at mid-span of the 3,000-foot bridge and approximately 275 feet above the ship canal below. The team staged a temporary beam parallel with the damaged stringer and secured it to the damaged beam with high strength rods to alleviate pressure from the damaged beam, which was still holding a section of the deck.
Once access was created, the Atkinson team performed jacking to tension the high strength rods and transfer the load from the existing stringer to the temporary support beam during demolition of the damaged sections. The team then performed rivet removal, cut out a section of the damaged beam, fabricated a new steel beam, and bolted it back to the existing stringer.
Initially expected to take 10 days to repair, the Atkinson team worked strategically and efficiently around the clock, to repair the bridge in just five days.
“Atkinson took the challenges and complexities of this emergency work and answered the bell,” said Messay Shiferaw, assistant regional administrator for WSDOT. “In every instance, their combined effort with Apex and Purcell made it possible to complete the work way ahead of schedule, providing early access to thousands of commuters.”
Eli Reddell, a project manager at Atkinson who led the emergency bridge repairs, attributes planning and assembling the right team for the early delivery.
“Thinking ahead and planning for each and every part of the project allowed us to seamlessly flow from one step to the next,” said Reddell. “That, coupled with knowing the right people to call and assembling a team quickly, led to a successful project.”
The repaired bridge reopened to traffic on November 6, providing thousands of commuters full access to SR 99 five days earlier than expected.