Time Lapse Video: Bellevue Light Rail Tunnel 1/3 Complete

BELLEVUE, WA - The construction of a light rail tunnel under downtown Bellevue hit a major milestone recently. The tunnel is now one-third complete toward its eventual length of approximately 1/3 of a mile.

Construction crews are working from a pit at the south end of the tunnel near the intersection of 112th Avenue Northeast and Main Street. The tunnel will exit on the north end of 112th Avenue near Bellevue City Hall.

The light rail tunnels in Seattle were built with a boring machine, but the Bellevue tunnel is being build using a method called sequential excavation. With that method, an excavator scoops away sections of soil and then pressurized concrete is sprayed on the walls to provide structural support. The entire East Link line is expected to open in 2023.

Watch the time lapse video below to see how it's done:

Image via Sound Transit