Alaskan Way procurement - TunnelCast
Video courtesy of WSDOT

October 2010: A giant TBM bored tunnel of 54ft (16.5m) diameter or more will replace the earthquake-damaged elevated SR-99 highway across the waterfront of Seattle, Washington.

Alaskan Way mega-project procurement - TunnelTalk, Oct 2010
Proposals called for Alaskan Way tunnel - TunnelTalk, May 2010
Taking mega TBMs to greater limits - TunnelTalk, June 2010

Snapshot

Alaskan Way bored tunnel alignment

Location:
Seattle, Washington, USA
Dimensions:
Single bore segmentally lined TBM tunnel of 54ft (16.5m) diameter or more, passing 9,100ft (2.7km) under downtown Seattle at depths ranging from 60ft to 200ft (18-60m)
Type:
Double-deck highway tunnel
Owner:
Washington State Department of Transportation
Project Value:
An estimated $1.69-2.1 billion
Project procurement:
Proposals for a design-build construction contract are due on Friday 28 October
TBM:
Specified closed-face pressurized TBM of minimum 54ft (16.4m) diameter
Contract Award:
Scheduled for January 2011
Project opening:
Targeted for 31 Dec 2015