Ebey Slough Bridge Replacement, Marysville, Wash.
The new Ebey Slough bridge replaces an 86-year-old steel truss bridge with a higher and wider steel-girder span. The project included doubling the bridge's capacity to four lanes from two as well as adding two bike lanes and sidewalks. In addition, the new bridge was built high enough for marine traffic to pass without the need for a swing span.
The project also included demolition of the old span. This involved sheet pile cofferdams for pier demolition, contaminated soil removal and sediment capping.
The team was also able to salvage several sections of the old bridge's control house, sections of its swing span mechanisms and sections of the decorative barriers that will be used as part of a memorial to the old historic bridge.
The most challenging aspect of the project was working in an environmentally sensitive area that required 18 permits during construction. Most of these involved specific in-water work, which required crafting plans for work access, bridge demolition, bridge rest removal and sediment mount excavation that had to be scheduled around tidal conditions and short-work windows.
The $21.5-million project is the Washington State Dept. of Transportation's first to use reinforced concrete-filled tubes. The tubes, which had 6-ft and 4-ft diameters that extended 240 ft deep into the soft alluvium deposits, are the deepest to date in the state.
Keeping the inside of the steel piles clean was vital. To achieve this, the team used several methods, including pressure washing to remove soil from inside the tubes.
Construction on the new bridge was completed ahead of schedule and under budget. Out of a total of 58,470 hours worked, the project was delivered with no lost-time accidents or OSHA recordable incidents.
Owner/Developer; Lead Design Firm; Structural and Civil Engineer Washington State Dept. of Transportation
General Contractor Granite Construction Co.
Steel Cased Shafts/Cofferdams/Bridge Rest Removal Pacific Pile and Marine
Stone Column Ground Improvements Hayward Baker
Structural Steel Erection Apex Steel Inc.
Rebar R2M2 Rebar and Stressing
Bridge Demolition Station Cos.
Electrical Specialized Pavement Markings
Landscaping Terra Dynamics Inc.
Survey Harmsen and Associates
Flatwork Salinas Construction
Pavement Removal PR Systems Inc.