Weekly Update: West Seattle High-Rise Bridge Stabilization

West Seattle Bridge at sunset. Photo Credit: Madison Linkenmeyer

Every Monday, we’re posting a blog to keep you informed about our progress to stabilize the bridge, our efforts to address traffic and mobility, and other items related to the West Seattle High-Rise Bridge closure. 


In this week’s update: 


High-Rise Bridge Stabilization 

Kraemer North America, our contractor for the stabilization work, is working every week, Monday through Saturday from 6 AM to 4:30 PM, to stabilize the bridge. 

Stabilizing the High-Rise Bridge is necessary to preserve public safety and the integrity of the bridge so all options remain on the table for a repair or replace decision. Stabilization puts us on the right path if repair is determined to be the best option. If we move forward with replacement, stabilization ensures no further damage is done and that the public is kept safe during design and construction of the replacement.  

View from above: A crane barge passes beneath the work platform suspended from the West Seattle High-Rise Bridge. 

The table below outlines details on recent and upcoming West Seattle Bridge-related work.

Recent and Upcoming WorkDetails
The stabilization work is expected to continue for the next several months and includes:  
Carbon fiber wrapping weakened areas of the bridge; adding post-tensioning inside the girders; injecting epoxy into cracks that are wider than 0.3mm. The epoxy injections don’t stabilize the bridge; they help prevent further deterioration by protecting the post-tensioning steel inside from corrosion.  

This coming week, the contractor is planning to:  
Install the post-tensioning system; prep for Pier 18 release; the release could happen as soon as the week of October 19. 

During daily work, you may see:  
Crews working on top and under the bridge; scaffolding and crews working on platforms suspended under the bridge; large equipment and vehicles delivering, moving, and storing materials.  

There is also work taking place inside the bridge that you will not be able to see: 
Monitoring cracks, and installing the additional post-tensioning strands. 

Over the next few weeks, the contractor will:  
Continue stabilization work listed above and work to “release” the restrained bearing at Pier 18. We could be doing the Pier 18 “release” as soon as the week of October 19. Leading up to the Pier 18 “release”, the contractor will be installing a post-tensioning system inside the girder. 

Other stabilization work will include: 
Applying additional layers of CFRP to the girders after the Pier 18 release and post-tensioning are complete. Once all stabilization work has been finished, we will lower the work platforms onto barges (likely in late November).
  
Decisions in the coming weeks: 
We will make the final determination as to whether we will move forward with repairing the current bridge or replacing it with a new structure. With our replacement consultant HNTB on board, we are ready to pivot to designing the demolition and replacement structure, should it be determined that it’s in the public’s best interest to replace rather than repair.   

Since we closed the bridge in March, we have: 
Installed an intelligent monitoring system to better understand what type of stabilization and repairs would be needed and to monitor the bridge during this work; designed and started to install stabilization measures; built and hoisted custom work platforms; completed the first phase of carbon fiber wrapping; started the cost-benefit analysis (CBA) that will help inform the decision to repair or replace the bridge.    

Traffic Alerts:

We do not anticipate any additional traffic impacts from this work over the next few weeks.  While we do not anticipate significant impacts to traffic below the bridge, you may see some traffic control signs and devices. These signs and devices are meant to keep the workers and traveling public safe. Please obey the signs and do not move them. 

While the majority of the traveling public will see little to no traffic impacts during Pier 18 work, there may be lane reductions on Klickitat Ave SW and SW Klickitat Way on the west and south sides of Harbor Island. Please obey the traffic control signs and devices and do not attempt to move them. Our teams are coordinating closely with the Port of Seattle to mitigate traffic impacts. 

View from below: the two work platforms are suspended under the bridge, surrounded by the CFRP crews recently installed.
View from below: the two work platforms are suspended under the bridge, surrounded by the CFRP crews recently installed. 

We made progress on important projects over the past weekend.  

Tree Maintenance on West Seattle Bridge Trail  

On Friday, Oct. 3, we performed maintenance on the West Seattle Bridge Trail near the Chelan Café. Crews trimmed trees and other vegetation encroaching the trail.  

Concrete panels on SW Barton St 

On Saturday, Oct. 3, we replaced some concrete panels on SW Barton St approximately 100 feet on each side of the intersection with 32nd Ave SW. 

Intersection Restriping at West Marginal Way SW and Highland Park Way SW 

On Sunday, Oct. 4 as part of a series of projects along West Marginal Way, we restriped at the West Marginal Way SW and Highland Park Way SW intersection. This restriping (new paint markings) will help reduce wait times at the intersection and potentially get more cars through the signals when they’re green.  

Graphic of the restriping taking place on Sunday, Oct. 4
As shown in the map above, the right lane on westbound Highland Park Way SW – approaching the intersection – will now be a right-turn-only lane. The far left westbound lane will become a through lane. Left turns will no longer be allowed onto West Marginal Way SW from westbound Highland Park Way SW. For questions or more information about this work, please contact us at westseattlebridge@seattle.gov or 206-400-7511.  

The West Seattle Bridge Community Task Force will meet Wednesday, October 7 at 12 PM.  

The Community Task Force will hold its biweekly virtual meeting Wednesday, October 7, at 12 PM. All Community Task Force meetings are now streamed live on YouTube and we invite you to watch.  

Here is a link to watch the Community Task Force meeting on October 7 at 12 PM.  

The meeting will include a discussion with Mayor Jenny Durkan, an update on bridge stabilization work, and a thorough presentation and discussion on the cost-benefit analysis. The majority of the meeting will focus on the cost-benefit analysis in advance of the Mayor’s proposal for repair or replace, which will come later this month.  

There will be traffic impacts at the intersection of 1st Ave S, Myers Way SW, and Olson Pl SW the weekend of Oct. 10-11 to complete repaving. 

SDOT crews will be repaving this section of Olson Pl SW and 1st Ave S the weekends of Sept. 26-27 and Oct. 10-11.

This coming weekend, weather depending, our crews will complete repaving a section of Olson Pl SW and 1st Ave S at the intersection with Myers Way S. Olson Pl SW will be repaved at the intersection, and the southbound lane of 1st Ave S will be repaved just north of the intersection. We started this work the weekend of Sept. 26-27. 

Expect traffic impacts the weekend of Oct. 10-11 for this work. Traffic will be reduced to one lane in each direction during paving. Work will start in the early morning hours to open the travel lanes back up in the early afternoon both days. A noise variance will be issued to complete the paving. 

1st Ave S has become a heavily trafficked corridor as part of the detour route for the West Seattle High-Rise Bridge closure. While there is additional pavement along 1st Ave S in need of repair, our crews are prioritizing this stretch of the roadway that is in particularly bad shape to make sure we’re off the detour route in the early afternoon. We will continue to monitor the pavement along the detour route to determine where repaving and repair is needed. 

Visit our West Seattle High-Rise Bridge website to stay up-to-date on the bridge, see frequently asked questions, and view inspection reports. Also, take a look at all of our West Seattle Bridge blogs