Final repairs underway for the West Seattle Bridge

With the high rise West Seattle Bridge due to re-open on Sept. 19 the last of the repair work is now underway.

Photo by Patrick Robinson

As WestsideSeattle reported on Thursday the West Seattle High Rise bridge closed since March of 2020 is set to reopen on Sept. 18.

That opening will depend on the successful completion of remaining work including a final set of epoxy injections and carbon fiber wrapping, paving, installing safety inspection platforms inside the bridge, and robust safety testing. All restrictions on the Spokane St Swing Bridge (also known as the West Seattle low bridge) will end on the same day.

SDOT shared a press release describing the remaining work:

High bridge repair: crack injection and carbon-fiber work continue; sealing the post-tensioning system

SDOT repair graphic — A graphic of work status updates on the West Seattle High Bridge.

We continued progress on the final phase of epoxy crack injection and carbon-fiber wrapping this week. As we complete a section of carbon-fiber wrap work on the underside of the bridge, we move on to the next section by shifting work platforms along the rigging lines we installed last winter.

After we finish the remaining epoxy and carbon-fiber work, and after epoxy polymer infused in the carbon-fiber sheets has cured, we will be able to lower and remove the work platforms from the bridge.

more carbon fiber — Working from the platforms postitioned on the underside of the bridge, crews continue their progress on the final phase of carbon-fiber wrap work

We also sealed the post-tensioning system this week by injecting a grout compound into the post-tensioning ducts that contain the tightened cables. By filling the ducts with grout, we protect the steel cables from air and moisture, which prevents them from rusting. After filling the ducts with grout, crew members welded the ends of the post-tensioning anchors.

grout injector — Working from the platforms postitioned on the underside of the bridge, crews continue their progress on the final phase of carbon-fiber wrap work

The grout compound is pumped from the above machine down through the bridge deck and into the post-tensioning ducts, where it will envelope the steel cables and prevent them from rusting.

We made more progress on maintenance work and other activities needed to reopen the bridge. This work included more concrete pouring for the new overlayon the Fauntleroy Expressway, wire installation for the lights on the bridge, and continued assembly of the permanent inspection platforms that will be installed inside the bridge’s girders.

West Seattle Bridge Final Repairs Checklist

Completed: Let the post-tensioning concrete set and cure
Completed: Install post-tensioning ducts
Completed: Pre-tensioning epoxy injections and carbon-fiber wrapping
Completed: Install post-tensioning strands
Completed: Tension post-tensioning strands
In-Progress: Complete final epoxy injections and carbon-fiber wrapping
To do: Complete cure time for the carbon-fiber wrapping
To do: Remove work platforms
To do: Load test and inspect the repairs
To do: Restore the bridge deck
To do: Demobilize the site

WSB checklist

Robinson Papers

West Seattle Herald