The Manette Bridge was identified as both structurally deficient and functionally obsolete. As a result of this assessment, the bridge was added to the WSDOT Bridge Replacement Priority Array List in December of 1993.
The Manette Bridge was originally built in 1930. The bridge was constructed with five steel truss main spans on six concrete piers. A 1949 contract replaced the original wooden deck and timber trusses in the outer spans with concrete and steel. The primary areas of structural deficiencies are in the concrete piers and the structural steel trusses, which are nearing 80 years old. The concrete in the foundations is in varying states of deterioration.
Overall, the substructure components are in poor condition at the main piers (built in 1930) and in satisfactory condition at the approach piers (built in 1949). Columns and pier walls at the main spans exhibit leaching cracks, rust stains, delaminations, soft concrete, and formwork holes.
The foundation is exposed at all piers in varying degrees. Repairs to the main concrete piers were completed in 1949 (Piers 4 and 6) and 1991 (Pier 5) and 1996 (Piers 4 and 6). These repairs attempted to encase the deteriorating concrete in the concrete foundations but were not effective.
Based on these deficiencies as well as other considerations, it was determined that replacement of the bridge is warranted and necessary. The Legislature and the Governor have provided approximately $65 million for the replacement of the Manette Bridge over the next 8 years with construction of the new bridge scheduled to begin in 2010 although construction my be accelerated and begin in 2009.
The Manette Bridge is located in Bremerton, Kitsap County, Washington. The bridge spans the Port Washington Narrows, a 3.5 mile long and 0.25 mile wide fjord which connects Dyes Inlet with Sinclair Inlet. The bridge is critical to the Bremerton community, providing a link between the eastern and western portions of the city. The proposed project will replace the existing bridge with a new concrete bridge. The new Manette Bridge will be built parallel to and immediately south of the existing bridge. The project will take three years to complete.
The proposed project will replace the structurally deficient and functionally obsolete Manette Bridge with a new concrete bridge. The new Manette Bridge will be built parallel to and immediately south of the existing bridge, with roadway connections to existing city street intersections on each end of the bridge. Construction of the project is proposed to begin in 2010 and continue for approximately 3 years.
First, the new bridge piers and central portion of the new bridge will be constructed. Second, the outermost spans of the existing bridge will be removed and the new bridge’s outermost spans and abutments will be built. This work includes the completion of stormwater facilities for the new bridge. Finally, the remaining portions of the existing bridge will be demolished and removed. The construction elements associated with these phases are summarized below and detailed in the following section Construction Sequencing and Project Elements.
The demolition of the existing bridge will occur in phases over a period of 18 months. After the central portion of the new bridge is constructed, the outermost spans and abutments of the existing bridge will be demolished and removed. Once the new abutments and outer spans are constructed, the demolition of the remainder of the existing bridge will proceed.
The bridge structure above the water line will be cut into manageable sections, using conventional concrete and metal cutting tools, or a wire saw, and placed on barges for transport to approved waste or recycling sites. Pavement will be removed using a hoe ram. The portions of the piers below the water line will be cut into pieces using a wire saw. All slurry from wire cutting operations above the water line will be contained and removed; below the water line it will be dispersed by the current. The piers will be cut off at the ground level. Pier armoring will also be removed, although the exact amount is unknown. Based on the known quantities of rip rap placed around the piers and inspection reports, WSDOT estimates that approximately 12,000 cubic yards of riprap is currently in place around existing bridge footings, all of which will be removed. Because the new bridge will not have footings, riprap will not need to be replaced.