SATSOP – The construction of the test pontoon for the State Route 520 Bridge replacement is complete and a “complete success.”
“We’ve learned a tremendous amount,” said Scott Ireland, Washington State Department of Transportation’s (WSDOT) project engineer for the project which occurred on seven acres at Satsop Development Park in eastern Grays Harbor County.
While other aspects of replacing the SR 520 Bridge, which spans Lake Washington connecting Seattle and Bellevue, may have been more controversial, as far as the engineering science goes, the progress and advancements have been greater than expected.
“During the construction of the test pontoon, engineers identified opportunities for improvements in the form system, reinforcing details, concrete placement methods and the concrete mix design,” Ireland said, adding that they were surprised at how much they learned.
“This was essentially a research project intended to find as many problems as possible so we could identify them now, document them and address them in anticipation of the actual pontoon project,” he explained.
Wednesday marked the completion of the first phase of the project which included the construction of the test pontoon. Phase 2, which started Thursday, marks the first day of a suspension period to allow construction engineers, technical advisers from the WSDOT bridge design office and the designer-builder, Kiewit-General Joint Venture, to take a closer look at the completed structure and document and record observations. Demolition of the test pontoon, the third phase, is scheduled to begin on or before May 6, Ireland said.
Quigg Bros. Construction Co. of Aberdeen was awarded the $2.7 million contract with the WSDOT to do the testing construction and demolition.
With four floating bridges in the state, WSDOT is considered the world’s expert in design and construction of floating bridges. Each time they build one they carefully make a list of “lessons learned” to carry over to the next project, said Ireland, who was the construction manager on the Hood Canal Bridge project.
“Over the next two weeks, observations and lessons learned from this testing will be compiled to help facilitate the most efficient construction methods and produce the highest quality pontoons for the 520 Bridge,” Ireland said.
WSDOT has determined that the 33 pontoons – the biggest ever built in the state, each of them 75 feet wide by 360 feet long by 28.5 feet high – will be manufactured in Grays Harbor County. Upon final environmental review, a pontoon casting facility will be built at either the “preferred” site of the former Weyerhaeuser log sorting yard in Aberdeen or the 90-acre alternative site in Hoquiam owned by the Anderson-Middleton Company.
The test pontoon constructed at Satsop Development Park is 120 feet long, 38 feet wide and 28.5 feet tall, roughly one-sixth the size of the largest of the final pontoons WSDOT will build in Grays Harbor for the new SR 520 floating bridge.
“It’s been so fascinating to see the daily progress of the project,” said Tami Garrow, CEO of Satsop Development Park. “We’re so glad we were able to provide the perfect place to help this important project for our county and our state.”
“The Satsop Development Park provided us the access and the lay-down area that we needed to complete the project on such a short time basis,” Ireland said. “We didn’t even have to go through the permitting process because the site was already permitted for this kind of work.”
“We’re honored to be a part of the project and thankful to DOT for thinking of us. We would very much like to be considered for future DOT projects, as well as any others that require pad-ready sites,” Garrow said.
“It’s exciting for us to play a small part in this big operation that will bring so many new jobs to Grays Harbor.”
Satsop Development Park is a 1,700-acre mixed-use business and technology park located in scenic Grays Harbor County in Southwest Washington just 30 minutes from Olympia and the I-5 corridor. It is home to more than 30 businesses, offers 440 acres of developed, pad-ready land and buildings supported by super-sized infrastructure and surrounded by 1,200 acres of sustainable managed forestland.
The Park is managed by the Grays Harbor Public Development Authority, a public corporation whose mission is to create new jobs and investment for the region. More information on Satsop Development Park can be found at www.Satsop.com.