East Link Tunnel Excavation Nears Completion

July 3, 2018 - by Emma Sullivan


Category: What's Happening

East Link Tunnel Excavation Nears Completion


Emma Sullivan, July 3, 2018

If you haven't noticed the construction for Sound Transit's East Link light rail around Downtown Bellevue...you probably haven't been spending that much time in Downtown Bellevue. But, did you know that the tunnel is more than 90% complete?

It's true! Crews are expected to break through to the site of the future Bellevue Downtown Station in just a few weeks. This means that the tunnel is on track to be completed within fifteen months (five months faster than the original forecast). Crews have been working on the tunnel since February of last year and excavation started at the south portal site at 112th Ave. NE and Main. When complete, the tunnel will be approximately one-third of a mile long, running between the future East Main and Downtown Bellevue stations under 110th Ave. NE, turning east near NE 6th St.

Check out this incredible time-lapse showing excavation of the tunnel: 

Bellevue SEM Timelapse from Sound Transit Video on Vimeo.

You can also look at the tunnel from a 'flyover' perspective: 

Downtown Bellevue Tunnel South Portal UAV Flyover from Sound Transit Video on Vimeo.

Tunnel facts: 

  • The tunnel is 1,985 linear feet long (~1/3 of a mile)
  • The tunnel is 27 feet, 10 inches tall
  • The overall width of the tunnel is 34 feet
  • The tunnel is 12-30 feet below the surface depending on location
  • 72,000 cubic yards of soil have been removed to-date
  • Each side of the tunnel is 16 feet, 3 inches wide, with a center dividing wall (18 inches thick)
  • 479 lattice girders have been used

The future of East Link

The East Link project will extend light rail fourteen miles from Downtown Seattle to Downtown Bellevue and to the Overlake area of Redmond. The extension will follow I-90 and will add ten new stations. The entire line will be operational in 2023 after which Sound Transit will add an additional 3.7 mile extension further east to Southeast Redmond and Downtown Redmond. 

Learn More



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