Challenge Design-Build Project Delivery Addressed
The Washington State Department of Transportation (WSDOT) considered traditional delivery options but decided that the design-build model was a perfect fit for this project because design-build did several things: it allowed fast-track delivery of the new bridge replacing a vulnerable structure, it allowed greater innovation and potential cost savings to WSDOT, and it shifted appropriate project risk components to the design-builder.
The SR 520 Floating Bridge and Landings Project designed and built the world’s longest floating bridge, creating a safer, more reliable link between Seattle and the growing high-tech cities east of Lake Washington. With HOV lanes, full shoulders for disabled vehicles, a cross-lake bicycle and pedestrian path, and the largest, heaviest, and strongest bridge pontoons ever built, the new 1.5-mile-long floating highway dramatically improves the movement of people and freight in the Central Puget Sound region.
Client/Owner: Washington State Department of Transportation
Design-Builder: Kiewit/General/Manson, A Joint Venture
General Contractor: Kiewit/General/Manson, A Joint Venture
Architect: Helix Design Group
Engineers: KPFF Consulting Engineers, BergerABAM
Specialty Consultants: International Bridge Technologies, Wood Harbinger
Other Team Members: IBI Group, Hart Crowser, Geo Engineers, Floyd|Snider, WSDOT, HDR, EnviroIssues, Parametrix, Parsons Brinkerhoff
Duration of Construction: 56 months
Project Cost: $763,548,129