Tuesday, June 26, 2018

True Life: I’m a westbound Snohomish County trestle in need of preservation, pavement and completely dry weather

UPDATE
The closure of westbound US 2 scheduled Sept. 21-24 is postponed due to inclement weather in the forecast. The closure is rescheduled for 7 p.m. Friday, Sept. 28 to 4 a.m. Monday, Oct. 1.

Some US 2 drivers question how one project could “need it all” in the soggy Pacific Northwest

By Frances Fedoriska

We don’t like it either. If we asked Snohomish County travelers to pick a children’s tale they feel embodies the US 2 preservation project, we would not be surprised if “The Boy Who Cried Wolf” won by a landslide.

Four times now we have spread the word of six weekend closures of westbound US 2 between the SR 204 interchange and Homeacres ramp. Four times the forecast hasn’t been in our favor. Four times we’ve had to postpone the closures hours before their start time.

Rain is the culprit. Its trickle-down effect has disrupted routines, plans and frustrated drivers and contractor crews alike. We all want to finish the six closures for this project. We all want the Hewitt Avenue trestle rehabilitated and preserved so it can be in a good state of repair for years to come.

Absolutely no rain allowed

While many of our projects can continue in the rain, this is not one of them. The waterproof material we need to put down to prevent rainwater from seeping into the concrete bridge deck and corroding the rebar has to be applied when there is NO rain or moisture AT ALL on the bridge deck.
Lakeside crews applying waterproofing material to another project on a dry, sunny day
Two big reasons why.

First, the primer used to attach the waterproof coating to the bridge deck won’t stick if there is moisture on the concrete deck. Moisture prevents the primer from bonding and the coating from sticking correctly.

Secondly, applying the material when there’s a hint of moisture, then putting hot asphalt on top of the waterproof coating creates steam. That steam can expand, creating bubbles or separations between the bridge deck and asphalt. This derails some major goals of this project which include, but aren’t limited to: removing cracks and potholes (versus creating more of them), and providing a smooth ride on the newly rehabilitated trestle.

For these reasons, applying the material when there is any moisture voids the warranty. No one wants that.

But I-5 is getting repaved too

I’ve had a few of you ask why we can do Revive I-5 paving work when it rains a little in Seattle, but we postpone what appears to be similar paving work on US 2 in Snohomish County. It’s because the waterproofing material is only used on bridge decks. The Revive I-5 project only involves a little bit of bridge deck work. That project also postponed a weekend ramp closure in April when rain was expected.

Why weekends?

Our crews can get a lot more work done during a full weekend closure than during a quick, overnight closure. Overnight shifts only provide a few hours to get work done before we have to pack up our equipment and get off the roadway in time for the morning commute.

We need six weekend closures so we can:
  • Remove old, damaged pavement
  • Inspect the trestle
  • Make any needed repairs
  • Put down a new waterproof coating
  • Put down a new layer of asphalt
Weekend closures help shorten major preservation projects such as this one, and get commuters and commerce back on Washington’s freeways in a shorter amount of time.

When hoping for the best backfires

Everyone involved in this project knows the odds of having bone dry weekends – in the convergence zone - during May and June - weren’t in our favor.

But we had to try.

Our dry “construction season” is already limited here in the Pacific Northwest, between coordinating with other road closures, events and holidays. Still, we tackled this US 2 weekend closure schedule with an optimism usually reserved for romantic comedies and started with the hopes of closures in the spring.

Mark your calendars

That brings us to the updated westbound US 2 weekend closure schedule. As of this writing, these closures are tentatively scheduled for 7 p.m. Friday to 4 a.m. Monday on the following dates:
  • July 13 – July 16 COMPLETED
  • July 20 – July 23 COMPLETED
  • Aug. 3 – Aug. 6 COMPLETED
  • Aug. 10 – Aug. 13 POSTPONED due to weather
  • Aug. 17 – Aug. 20 COMPLETED
  • Sept. 7 – Sept. 10 POSTPONED due to weather
  • Sept. 14 - Sept. 17 POSTPONED due to weather
  • Sept. 21 - Sept. 21 POSTPONED due to weather
  • Sept. 28 - Oct. 1
  • Oct. 5 - Oct. 8
By now you know this, but it bears repeating: These closures are weather dependent.

The detour

For the first four weekend closures we will reverse traffic on 20th Street Southeast.

Westbound US 2 traffic between Lake Stevens/Snohomish and Everett should be prepared to use a detour during the full weekend closures of the trestle.


View larger US 2 closure map (pdf 811 kb)

Of course, 20th Street Southeast is a single-lane road and doesn’t have the space to efficiently move all the travelers who will be booted off westbound US 2 during these closures. Travelers need to:
  • Brace for congestion on nearby state routes 9, 96 and 528
  • Carpool
  • Take transit 
  • Move discretionary travel to a non-construction weekend
  • Travel before 8 a.m. or after 8 p.m. to avoid peak congestion
  • Check traffic conditions before you get behind the wheel
    • Our website will have closure and lane reduction updates.
    • Get weekly email updates on King and Snohomish County projects.
    • Our Twitter account will have info about traffic.
    • Download our mobile app for traffic maps and other news and updates.
Thanks in advance

There’s no good time to close an entire direction of US 2. However, doing this extensive preservation work will reduce the need for future emergency repairs that add time to already long commutes in Snohomish County. We appreciate any adjustments you make to help us complete this important rehabilitation work. We also thank those of you who indulge in any personal superstitions you believe will help ward off rain clouds.

3 comments:

Unknown said...

This project could have been broken into smaller bits using the ramp to drop below allowing work to be done on the longest stretch. The weather was only a factor late Sunday evening nearly both times. It seems that this project isn’t being managed very well. I’m sure you’ve heard it before. I can’t possibly be the only person that sees this.

Snohomish County Voter said...

Now that composite concrete reinforcements have been shown to provide waterproof alternatives to rebar and epoxy-coated rebar, why has WS-DOT not switched over to more durable concrete surfaces for our critical bridges? Why keep using the old asphalt top layer design when traction tires and freezing weather cause such rapid deterioration in our climate? Why has WS-DOT not just used the current older US-2 trestle as a form for a new all-concrete bridge deck?

WSDOT said...

Snohomish County Voter, when the trestle was built in 1968, bridge engineers chose to use asphalt with a waterproof coating overlay due to the unique way the trestle was structured. There may be more durable overlay types like modified concrete or polyester, but they are more expensive and would take more time to construct. There is also concerns that these more rigid overlay types would crack where the original precast units are connected down the longitudinal joint. From a practical solutions point of view, using an asphalt with waterproof coating on this bridge is the best compromise to balance all the constraints and minimize the impacts on the traveling public.

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