November 13, 2024

Piledriving work begins for new Portage Bay Bridge

WSDOT photo [enlarge]

A view from WSDOT traffic cameras last week shows a crane perched on a barge in Portage Bay.

Crews began piledriving in Portage Bay last week for the future westbound State Route 520 Portage Bay bridge.

The Washington State Department of Transportation says that this is the first of six possible piledriving seasons allowed on the project. The first of these, beginning this month and lasting through April, will be the most significant. WSDOT says that following seasons will have less piledriving activity.

The work is part of the SR 520 Portage Bay Bridge and Roanoke Lid Project, a $1.38 billion effort to replace the aging bridge with a seismically resilient structure. Two new parallel bridges — one for eastbound traffic and the other for westbound — will replace the 1960s-era bridge which is nearing the end of its functional life.

The new structures will have improved bus/carpool travel and an extension of the SR-520 Trail. The project also builds a landscaped lid between Seattle's Roanoke Park and North Capitol Hill neighborhoods.

Rendering from Skanska [enlarge]

The piledriving marks the beginning of work of the $1.38 billion 520 Portage Bay Bridge project.

Skanska is the lead on the design-build team; AECOM is the project's designer. Project completion is expected in 2031.

This project is part of the larger SR 520 Bridge Replacement and HOV Program. WSDOT calls this a key piece of the “Rest of the West” — which will finish improvements to the SR-520 corridor in Seattle. The Rest of the West projects were included in the SR 520 program's final environmental impact statement.

Another Rest of the West job, to the east of Montlake Boulevard, Graham Contracting is wrapping up construction on the Montlake Project. That $455 million effort involves two parallel west approach bridges over Union Bay, and includes a new landscaped lid between Montlake Boulevard and 24th Avenue East, as well as a bicycle and pedestrian land bridge east of the lid.

When the corridor's reconstruction is fully finished, WSDOT says that all of the SR-520 major bridges will be replaced with seismically stronger structures, and that bus and carpool lanes, as well as bike and pedestrian paths, will extend from Seattle to Redmond.