The Washington State Dept. of Transportation has qualified four design-build teams that will vie for a $1-billion contract to construct a deep-bore tunnel replacing the seismically unsound Alaskan Way viaduct in Seattle. The winner will begin work on the four-lane, 2-mile-long double-decker tunnel on state Route 99 after the award in late 2010.

A new tunnel (inset) will replace waterfront viaduct.

WSDOT on Dec. 18 announced the qualified joint-venture teams: Seattle Tunnel Partners, which includes Dragados USA Inc., Coral Gables, Fla., and HNTB Corp., Kansas City, Mo.; Seattle Tunneling Group, which includes S.A. Healy Co., Lombard, Ill., FCC Construction S.A., Madrid, Parsons Transportation Group Inc., Washington, D.C., and Halcrow Inc., New York City; VTS Joint Venture, which includes Paris-based Vinci Construction, Traylor Bros. Inc., Evansville, Ind., Skanska USA, New York City, and London-based Arup; AWV Joint Venture, which includes Kiewit Pacific Co., Vancouver, Wash., Germany’s Bilfinger Berger and AECOM Technology Corp., New York City.

The firms will provide details about design and construction for the five-year project, including specifications for an Earth Pressure Balance tunnel-boring machine. “They have to take into account our very abrasive soils, the production speeds and maintenance requirements,” says Linea Laird, director of Central and North Projects for the replacement program. “We will include some performance criteria.” The draft RFP is due in January, says Bill Mariucci, Kiewit Pacific area manager. “We will [then] know more details about what is required.”

WSDOT will pay $2 million to each losing team, says Ron Paananen, the agency’s program administrator. Environmental review of the proposed bored tunnel is under way, and a supplemental draft environmental-impact statement will be available for public comment in 2010.

The final alignment is still being determined. On Dec. 17, WSDOT announced plans to shift the alignment west, to avoid causing settlement in a historic part of Seattle. Consultants are studying 300 downtown buildings to see if they can withstand settlement. The contract will call for advanced mitigation by the contractor, says Laird. Nevertheless, “we do not expect them to take 100% of the risk,” says Paananen. “We are really looking for a best-value proposal. We will also build in a healthy contingency fund.”