Final phase of repairs to West Seattle Bridge begin this month; expect to see crews

The final phase of repairs to the West Seattle Bridge will start this month, and the Seattle Department of Transportation says residents can expect to see construction crews on the bridge in the coming days.

The work is meant to augment emergency stabilization repairs made to the bridge last year after the department discovered rapidly growing cracks along the main span. The bridge has been closed since March of 2020.

The department made a number of repairs to ensure the bridge didn’t collapse.

Crews filled the cracks with epoxy, which acts like a glue that will keep the cracks from expanding. They then wrapped the cracked locations with carbon-fiber-reinforced polymer, which helps hold the bridge together through sheer force the same way a cast holds a broken bone in place during the healing process. They also installed new steel cables inside the bridge which — when tightened — allow the concrete to flex, which keeps the bridge sturdy as vehicles travel on it.

That work was finished in December of last year. Since then, the department has been planning the final phase of repair work, ordering bridge parts and selecting the contractor that will actually make the repairs.

The final phase of repair work, which starts this month, includes filling the cracks with more epoxy, wrapping additional sections of the bridge’s main span with carbon-fiber-reinforced polymer and adding another slew of post-tensioning steel cables. The department also plans to wrap some side spans with carbon-fiber-reinforced polymer during this phase.

The work is expected to be done some time in the middle of 2022.

Once finished, the department expects the bridge to last between 15 and 45 years. However, the city says it will replace the bridge when the time comes, and has already begun analyzing viable replacement options.

The city expects the repair work to cost about $94 million.