The ABCs of Bridge Replacement
Thanks to Omega Morgan and the process of Accelerated Bridge Construction, replacing the Puyallup River Bridge was a weekend project. Holly Zander reports.
Replacing the deteriorating and aging State Route 167 Puyallup River Bridge in the City of Puyallup was a priority for the Washington State Department of Transportation.
After serving for 90 years as an important connecting route in the Puget Sound and alternate to Interstate 5, the steel truss bridge had become structurally deficient and functionally obsolete. In recent years, due to deteriorated floor beams, a load restriction was put in place requiring vehicles larger than 10,000 pounds gross weight to use one lane only.
The $31.2 million design-build project traded the existing northbound steel truss bridge for a new two-lane structure. A plan was put in place to reinforce the bridge so trucks could continue to drive over it while construction began on the new northbound span.
“The new bridge is built to modern engineering and earthquake standards,” said WSDOT Project Engineer Dewayne Matlock. “The new bridge removed the height and weight restrictions we saw on the 1920s bridge, which was pretty important to the trucking community that makes up 10 percent of the traffic that uses the bridge.”
Before the new bridge could open to traffic, however, crews had to move the steel truss bridge out of the way. In came Omega Morgan, whose crews made the move look easy.
“Omega Morgan's attention to detail in the engineering and planning of the steel truss bridge move was extremely impressive,” said Matlock. “They are very competent in what they do.”
Traffic was shut down over one weekend in August so that a team from Omega Morgan could remove the bridge that was no longer being used and move it to a storage yard a quarter mile away.
Weighing in at 850,000 pounds, the old steel bridge was jacked 21 feet in the air using hydraulic jacks and slid 60 feet onto 24 dollies that were parked on the new bridge that was completed earlier in the summer.
Once loaded, the bridge was transported just a quarter of a mile away to a laydown site where the Washington State Department of Transportation will determine the bridge’s fate. The move went so well that traffic south was opened 17 hours ahead of schedule and traffic north 14 hours ahead of schedule.
The 1920s bridge will remain stored on-site for up to four years while WSDOT works to find a way to reuse it, perhaps as part of a pedestrian trail. If unsuccessful, the steel will be recycled.
Not a unique problem
The problem in Puyallup is not an uncommon one. According to the latest National Bridge Inventory released by the Federal Highway Administration there are over 215 million daily crossings on more than 61,000 structurally deficient bridges across the United States. These bridges are safe to use but need significant maintenance or repair to remain in service. Another 83,000 are functionally obsolete, and while they may be in good working order, they fail to meet current standards and need to be upgraded when it is time for them to be replaced. That is nearly one quarter of the total 607,000 bridges across the country.
Federal, state and local governments have been investing heavily in bridge maintenance and repairs; however, the Federal Highway Administration (FHWA) estimates that to eliminate the nation’s bridge deficient backlog in the next 12 years, investment in bridge repair and replacement would need to be increased by 60 percent.
Continued funding issues and challenges means a number of project delays across the country. To address those delays and make the most of available dollars, Accelerated Bridge Construction (ABC) is becoming more and more the preferred method.
ABC uses state-of-the-art planning and construction approaches to limit the onsite construction time that occurs when building new bridges or replacing existing bridges.
There are many advantages of accelerated construction including reduced traffic impacts, reduced construction time, reduced need for detours, and improved site constructability and worksite safety.
Often the cost of traffic detours that result from the closure of a bridge during new construction can actually surpass the cost of the new bridge structure itself. Closures in large metropolitan areas, or heavily travelled thoroughfares, can have a substantial economic impact on the businesses in the region.
From a cost savings standpoint, accelerated construction means that DOTs can replace bridges within just a few days, reducing planning and construction efforts by years. Not only does this potentially save money but it means that drivers and will see less of an impact on their lives and businesses can return to normal operations more quickly.
“The issue of aging bridge infrastructure, like in Puyallup, poses a significant opportunity for Omega Morgan to partner with transportation departments and engineering and construction companies across the Northwest and the country,” said Greg Tansey, CEO, Omega Morgan. “We hope to do more work like this with in the near future because it gives us the chance to work on projects that impact communities both large and small. We pride ourselves on delivering top notch engineering to solve the most complex of challenges, and these accelerated construction projects provide us the opportunity to do just that.
Omega Morgan’s Vice President of Engineering Ralph DiCaprio, is no stranger to bridge moves. His resume includes the complicated removal of Portland’s Sauvie Island Bridge and installation of the new bridge, managing the Third Avenue Bridge project in New York City, moving two 900-ton spans on the Hood Canal Bridge and the transport and launch of the Kalama River Bridge.
In early 2013, DiCaprio devised a plan to move the historic 1,100-foot-long, 3,400-ton bridge Sellwood Bridge in Portland, OR. It was deemed the longest, most complex translation ever completed and it happened in less than one day.
Another recent bridge translation completed on DiCaprio’s watch was the Skagit River Bridge in Washington. After being struck by a truck, the Skagit River Bridge collapsed. More than 71,000 drivers use this main connecting route each day so it was paramount to be able to quickly replace the collapsed bridge. In just under six months, contractor crews removed the collapsed bridge, put a temporary span in place, constructed a new span and Omega Morgan was responsible for jacking and sliding that new span to its permanent home. That move also took less than one day to complete.
When asked about the opportunity to move more bridges in the future, DiCaprio says the team is up for any task. “No two projects are the same, we move everything from massive transformers to delicate high-tech equipment. Each move poses its own unique set of challenges and the fun is in finding the most efficient way to get the job done and having our crew do it safer and faster than anyone else.”