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: 


West Seattle High-Rise Bridge Stabilization 

Stabilizing the West Seattle 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 and helps prevent further crack growth. Stabilization is also necessary for safe demolition if we choose to replace the bridge.  

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. We expect that stabilization work will be complete by the end of the year. 

The table below provides details on recent and upcoming West Seattle Bridge-related work:

Recent and Upcoming WorkDetails
The stabilization work we expect to be complete by the end of the year 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. Monitoring and inspection activities will continue even after stabilization work is complete, in both the repair and replacement scenarios.   

This coming week, the contractor is planning to:   
Finish installing and testing the post-tensioning system, mobilize for the Pier 18 release, and release the restrained bearing at Pier 18 as soon as the end of the week. 

 
During daily work, you may see:   
Some crews working on top and under the bridge, scaffolding and crews working on platforms suspended under the bridge, and 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. 

Upcoming work includes:   
After the Pier 18 release and post-tensioning are complete, Kraemer North America will do other stabilization work including applying additional layers of CFRP to the girders and rebuilding the Pier 18 bearing. Once all stabilization work has been finished, we will lower the work platforms onto barges. This will likely be in late November or early December.  

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.   

Over the past few weeks, we have: 
Poured concrete for the deviator blocks, which will keep the post-tensioning strands from touching the bottom of the girder as they travel between anchor locations; poured concrete for the last grout pads to cement the post-tensioning brackets to the interior girder floor; received post-tensioning tendons; and installed mounting hardware on the underside of the bridge girder to hold the post-tensioning brackets.

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; and 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 the work taking place inside the bridge 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.  

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 all traffic control signs and devices and do not attempt to move them. 

West Seattle Bridge Community Task Force Meeting 

The West Seattle High-Rise Bridge Community Task Force will hold its biweekly virtual meeting Wednesday, October 21, at 12 PM. 

Use this link to watch the meeting. 

The meeting will include updates on bridge stabilization work and the Reconnect West Seattle implementation plan, a presentation with time for Q&A on a rapid span replacement option, and an update on the cost-benefit analysis with Task Force discussion. 

Community Task Force meetings take place every other Wednesday at 12 PM and are now streamed live on YouTube. We invite you to watch.

Nearby & Recent Work 

New concrete bus stop platform at West Marginal Way SW and Highland Park Way SW 

This past weekend, SDOT crews built a new concrete bus stop platform at the northwest corner of the West Marginal Way SW and Highland Park Way SW intersection. This new bus stop platform is being installed in advance of King County Metro moving its existing bus stop at the intersection from the northeast corner to the northwest corner. 

Tree trimming on westbound Olson Pl SW 

On westbound Olson Pl SW, SDOT crews worked to clear obstructed signage and street lights, as well as clean up debris from last week’s wind event.  

Upcoming Community Outreach 

SDOT staff and community members on a recent walk through the South Park neighborhood.

Our outreach team is continuously connecting with the community to gather input and hear about day-to-day experiences in West Seattle and the Duwamish Valley. Below is a list of our upcoming events: 

  • Monday, Oct. 19: Georgetown Community Council meeting
  • Tuesday, Oct. 20 and Wednesday, Oct. 21: Highland Park neighborhood Home Zone walks
  • Wednesday, Oct. 21: West Seattle Bridge Community Task Force meeting
  • Thursday, Oct. 22: West Seattle Transportation Coalition meeting
  • Wednesday, Oct. 28: Highland Park Action Coalition meeting

Visit our West Seattle High-Rise Bridge website to stay up-to-date on the bridge, see frequently asked questions, view inspection reports, and find links to our West Seattle Bridge blogs