WSDOT Signs $1.35B Design-Build Contract for Alaskan Way Viaduct Project
Tuesday, January 11, 2011 22:39
Last Thursday, the Washington Department of Transportation signed a $1.35 billion contract with Seattle Tunnel Partners to design and construct a tunnel to replace the Alaskan Way Viaduct near Seattle’s waterfront. Seattle Tunnel Partners – a joint venture between Dragados USA and Tutor Perini Corporation – was identified last month as the best value proposer.
An engineering marvel, the proposed tunnel is expected to be 200 feet below downtown Seattle. It will have an approximate exterior diameter of 55 feet and an approximate length of 1.7 miles. http://www.wsdot.wa.gov/Projects/Viaduct/Questions.htm#11.
The tunnel will accommodate a 32-foot wide roadway with a 15 foot vertical clearance. http://www.wsdot.wa.gov/NR/rdonlyres/35FAE5C0-C79F-496D-9354-DEC2E4E98819/0/SR99BoredTunnel_STP.pdf
The RFP included a suggested substantial completion date of November 1, 2016. But Seattle Tunnel Partners expects to have it completed by December, 2015. Subcontractors include Frank Coluccio Construction and Mowat Construction for construction and HNTB Corporation and Intecsa-Inarsa for design.


