Construction crews have spent the past several months transforming the landscape around Northeast 18th Street and Interstate 205 in preparation for a new interchange there.
Now comes the heavy lifting.
Workers this week began hoisting massive steel girders that will form the backbone of one of the ramps at the new junction. The giant beams, the largest of which are 114 feet long and more than 84,000 pounds each, are being placed in sets of three each night through Friday, according to the Washington State Department of Transportation.
“There’s a lot of organization involved with it,” said Brad Clark, a design and construction engineer on the project. “There’s a lot of work to be done in a short amount of time.”
The setting of each girder involves a carefully orchestrated process, Clark said. The beams are brought in on special trucks from Tigard, Ore., then lifted into place using a large crane next to the freeway. Workers must secure the piece before the crane can “let go,” Clark said. Then, additional crossbeams are placed around the girders during the day.
The window of work is 8 p.m. to 6 a.m. each night — a schedule chosen to minimize traffic impacts, according to WSDOT. While the girders are on the move and in the air, lane closures and slowdowns on southbound I-205 are necessary, Clark said.
“It’s a pretty safe process, but you never know what can happen with a piece that big of steel,” he said.
The work is part of a $40.6 million project that will connect I-205 and 18th Street with a “half-diamond” interchange, putting ramps only to the south of 18th Street. Northbound freeway traffic will be able to exit directly onto 18th Street; an onramp will send vehicles from 18th Street onto I-205 heading south.
The steel girders, 15 in all, will only be used for the onramp on the southbound side of the freeway. The northbound offramp will be built on an earthen foundation, Clark said.
The final girders will be placed overnight Friday into Saturday morning, said WSDOT spokeswoman Tamara Greenwell. But there’s plenty of work still to come in the fall and winter months: concrete work, grading, sound walls, drainage work and other jobs, she said.
The 18th Street interchange aims to reduce congestion and improve connectivity in the area, according to WSDOT. The project is a companion to an earlier effort that rebuilt the convergence of I-205, Mill Plain Boulevard and Northeast 112th Avenue nearby.
Construction on the 18th Street interchange began in 2014. It’s expected to wrap up next year, according to WSDOT.
