Expansion joints can be constructed in different ways under state design standards for bridges. Shown is a plate cover joint (left) on the Highway 99 George Washington Memorial Bridge over Lake Union in Seattle and a concrete header joint (right) on southbound I-5 at the Duwamish River in Tukwila. These are similar to two types of expansion joints now used on the U.S. 2 bridge over the Pilchuck River in Snohomish County. (WSDOT photos)

Expansion joints can be constructed in different ways under state design standards for bridges. Shown is a plate cover joint (left) on the Highway 99 George Washington Memorial Bridge over Lake Union in Seattle and a concrete header joint (right) on southbound I-5 at the Duwamish River in Tukwila. These are similar to two types of expansion joints now used on the U.S. 2 bridge over the Pilchuck River in Snohomish County. (WSDOT photos)

About expansion joint covers on US 2’s Pilchuck River Bridge

One lane has a reinforced concrete-type header instead of a plate. Both are used on other bridges.

SNOHOMISH — Rick Lescher, of Snohomish, wrote in about what’s become a source of angst for Street Smarts readers: “Was wondering why one of the expansion joint gap covers has been missing for seems like around two years now on westbound Highway 2 near the Pilchuck River crossing?”

This column has fielded two other closely related questions in the past year, including one we printed a response for back in February.

This westbound approach to the Pilchuck River bridge has, indeed, turned out to be a bit of a problem spot.

“WSDOT has had to repair the U.S. 2 Pilchuck River Bridge expansion joints a couple of times the past few years,” spokesman Tom Pearce said.

The twist this time is that it’s the fix that drivers think is broken.

Let’s back up a bit.

Expansion joints allow bridges to flex with changing traffic volumes and weather. To drivers, they often appear as small gaps in the roadway. There are lots of parts, which means there’s plenty that can go wrong or wear out over time.

Replacing expansion joints can involve time-consuming closures, as was the case on I-5 in 2016 when WSDOT replaced expansion joints over Ebey and Steamboat sloughs — dubbed “the worst of the worst” at the time.

More often, it’s maintenance and small fixes along the way.

Enter our problem spot.

Cover plates were used to reinforce and span the expansion joint gaps at the east and west ends of the U.S. 2 Pilchuck River bridge. But the plates kept failing to hold westbound at the east end.

So WSDOT crews removed most of the plates, in stages, over the westbound lane. (One plate that covers the center of the roadway still extends a bit into the lane.)

Instead of cover plates, the expansion joint in the westbound lane at that spot is now reinforced with concrete-type headers. (For armchair engineers: Both types “provide a rigid lateral support to the expansion joint device and serve as a transition between the [hot mix asphalt] overlay material and the expansion joint itself,” according to the state bridge design manual.)

“The new concrete joint is just as safe and effective as the old one,” Pearce said.

It’s also the more common treatment for expansion joints statewide, and especially in Snohomish County.

“Most joints are concrete headers,” Pearce said. “I can say that in this part of Snohomish County this is the only bridge with cover plates.”

Inside the gap itself is a “flexible rubber gland.” This seal is placed below the surface of the road to avoid damage from passing vehicles.

For what it’s worth, there’s a slight bump as you drive over either type of expansion joint on that bridge.

It’s hard to say why this particular spot has had so many repair needs.

“It may have something to do with the approach that is on a curve to the left at that point. It could be due to the weight of traffic going in that direction, like log trucks and semi-trucks,” Pearce said. “It could also be the cover plate at that joint may have become fatigued, cracked and then just failed.”

As for further improvements, the road surface is scheduled to be repaved in 2019.

The bridge itself is in good shape. The Pilchuck River Bridge was built in 1983 and has a sufficiency rating of 84.73 out of 100.

Melissa Slager: streetsmarts@heraldnet.com; 425-339-3432.

Talk to us

More in Local News

NO CAPTION NECESSARY: Logo for the Cornfield Report by Jerry Cornfield. 20200112
Inslee: The president made me speed up teacher vaccinations

Here’s what’s happening on Day 54 of the 2021 session of the Washington Legislature.

Washington State Governor Jay Inslee speaks with special ed Pre-K teacher Michelle Ling in her classroom at Phantom Lake Elementary School in Bellevue, Wash. Tuesday, March 2, 2021. (Ellen M. Banner/The Seattle Times via AP, Pool)
Governor: Educators are now eligible for coronavirus vaccine

“This should give educators more confidence,” Jay Inslee said. Other frontline workers could soon be next.

Frances McDormand in "Nomadland." (Searchlight Pictures) 20210304
Masked in a nearly empty theater, a movie outing at last

Just four of us were in the audience for a matinee showing of “Nomadland” at Stanwood Cinemas.

James Myles walks his 5-month-old Pembroke Welsh Corgi Ellie around Martha Lake Park on Tuesday, March 2, 2021 in Lynnwood, Washington. Myles entered Ellie into a contest called Americas Favorite Pet, where she's currently in 2nd place for her group. (Andy Bronson / The Herald)
Vote for Ellie: Fluffy corgi from Lynnwood vying for top dog

“Her Fluffiness” is competing to be America’s Favorite Pet. The contest raised $300,000 for PAWS last year.

A view of the courtyard leading to the main entrance of the new Stanwood High building on Thursday, Jan. 21, 2020 in Stanwood, Washington. (Andy Bronson / The Herald)
Law gives Washington high school seniors leeway to graduate

Gov. Jay Inslee signed a bill that can waive some requirements for students who were on track before the pandemic.

A Marysville Pilchuck football player sports a spear on his helmet as the Tomahawks took on Snohomish in the Wesco 3A Championship Friday evening at Quil Ceda Stadium on November 1, 2019. School district leaders may soon need to consider dropping Marysville Pilchuck High School’s mascot, the Tomahawks. (Kevin Clark / The Herald)
Should Marysville Pilchuck High drop the name ‘Tomahawks’?

A state bill would ban Native American mascots and symbols from schools — unless there is tribal permission.

Snohomish County Council delays education spending vote

The council is now slated to decide next week on the measure, which targets a pre-K learning gap.

Erin Staadecker (left-right) Jael Weinburg and Kaylee Allen with Rosie formed the Edmonds firm Creative Dementia Collective. The company helps memory care patients and care-givers by providing art, music and other creative therapies. (Kevin Clark / The Herald)
This startup offers artful therapy for dementia patients

Creative Dementia Collective uses art and music to help them — and their caregivers.

Darlene Tanis sorts through book titles Thursday morning at the Everett Library on March 4, 2021. (Kevin Clark / The Herald)
Shrinking the ‘digital divide,’ area libraries slowly reopen

This week, services such as computer and Wi-Fi use — and even book-browsing — were reinstated.

Most Read