PACIFIC NORTHWEST EDITION
A Supplement to:
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July 28 2024 Vol. VIII • No. 15
“The Nation’s Best Read Construction Newspaper… Founded in 1957.” Your Pacific Northwest Connection – Sharon Swanson – 1-760-518-4336 – sswanson@cegltd.com
Spanning Success AECON Installs 50-Ton Girders for New Washington Bridge Construction crews from design-builder AECON are progressing on the Washington Department of Transportation’s (WSDOT) nearly $200 million I-90 — SR 18 Interchange Improvements project. As part of the overall project, the construction of a new bridge along SR 18 near Snoqualmie is a major part of the upgrades. Recently, crews installed four girders more than 50 ft. above the Raging River. The new bridge will span the entirety of the Raging River valley. Each girder section weighs more than 51 tons, which were lifted into place with two large hydraulic cranes. When complete, this second Raging River bridge will carry two lanes of westbound SR 18, while the existing bridge will carry two eastbound lanes. The project already has seen the construction of a new four-lane bridge over Lake Creek and crews are building another four-lane bridge over Deep Creek just east of the existing roadway. Growth in Snoqualmie Valley has made the I-90/SR 18 interchange one of the busiest in the state, causing backups during peak times and busy travel weekends. To improve traffic flow, WSDOT has handed out contracts for numerous upgrades that include: • Design and construction of a four-lane diverging diamond interchange; • Widening of SR 18 to four lanes from the interchange to Deep Creek; • Design and construction of a four-lane bridge over Deep Creek and a two-lane bridge over Raging River. “The diverging diamond interchange will improve the flow of traffic by reducing the number of traffic signals and offering more free turns for drivers entering and exiting the interstate,” AECON said in a statement. “Growth in Snoqualmie Valley has resulted in the current I-90/SR 18 interchange being one of the busiest in Washington
Overall, the project consists of widening of SR-18 to four lanes from the interchange to Deep Creek; design and construction of a four-lane bridge over Deep Creek and a two-lane bridge over Raging River.
State.” The first stage of construction began in April 2023. Contractor crews cleared trees in the project area to begin work on the new interchange and highway widening. To create enough space on SR 18 for a safe work zone, WSDOT and its contractor reduced lanes to one lane in each direction and shifted traffic to the east side of the roadway. In August 2023, crews shifted traffic to west side of the newly constructed Lake Creek bridge. A variety of construction activities are taking place throughout the project area. Some of this work includes: • Building the new two-lane bridge over Raging River
on SR 18, which will carry westbound traffic next to the current bridge; • Building the new four-lane bridge over Deep Creek on the east side of the roadway; • Finishing touches on new four-lane bridge over Lake Creek; • Grading area for two new SR 18 between Deep Creek and I-90; • Grading and preparing areas for new on- and offramps between I-90 and SR 18 at the new interchange; • Building a new drainage system at the interchange; see SPAN page 6