U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
The Carquinez Bridge is actually twin steel cantilever truss structures carrying I-80 across the Carquinez Strait from Vallejo to Crockett in the northeast San Francisco Bay Area. The original bridge was opened to traffic in 1927 and the second structure, which now carries eastbound I-80, was added in 1958.
The 1927 bridge will be replaced with a suspension bridge and the 1958 bridge will be retrofitted to withstand expected seismic loads. Construction will begin with retrofitting the 1958 structure in the fall of 1997 and will be completed with demolition of the existing 1927 bridge in spring of 2002. The suspension bridge is estimated to be open to traffic by November 2001.
The Benicia-Martinez bridge, which carries I-680 over the Carquinez Strait from Benicia to Martinez, is one of the retrofits that also includes adding additional capacity. The existing 6215 ft. steel deck truss will be extensively retrofit and an additional parallel structure will be constructed. Retrofit of the existing bridge will include hinge retrofit, footing tiedowns, footing enlargement and addition of drilled shafts, cable restrainers, and installation of isolation bearings. The new structure will be a post-tensioned precast segmental bridge, which will add five lanes of traffic capacity.
Retrofit of this 6062 ft. suspension bridge near Long Beach, California, includes foundation enlargement, column wraps, bent cap and abutment bolsters and tie rods in the superstructure. Red lead paste is being used as corrosion protection for the suspension cables. Construction began in early 1997.
For more information, check out the Vincent Thomas reftofit page.
The Coronado bridge is approximately two miles long, with steel box girders on the main spans and precast prestressed concrete girders on the approach spans. Retrofit includes installation of isolation bearings, installation of viscous dampers, concrete encasement of columns, strengthening of pile caps, and jacketing of marine pier piles. Murals painted on the approach piers are to be saved, requiring special design considerations in order to adequately strengthen the columns.
The 7.1 mile San Mateo Bridge will be retrofit and widened. The original structure was constructed in 1967 and consists of steel plate girders over the main spans and approximately 5 miles of trestle. Retrofit strategy includes bearing seat extensions, steel column casings, and foundation overlays or drilled shafts for belled pile foundations. The widening will be accomplished by constructing a separate 60 ft wide trestle with precast prestressed girders the full length of the existing trestle.
This 21,000 ft. steel truss structure carries I-580 across the San Francisco Bay from Pt. San Quentin in Marin County to Richmond.. The retrofit strategy consists of replacing the west trestles, retrofitting the east and west approaches, and strengthening of the truss foundations, substructures, steel towers, and superstructure. Foundation retrofits will include use of micropiles, as well as drilled shafts as large as 11 ft in diameter. Isolation bearings will be installed, and specifications will be based on the recent work done under HITEC.