The New Carquinez Bridge - Design Advancements

摘要

The new Carquinez Strait Bridge will be the first major suspension bridge to be constructed in the United States since the second Chesapeake Bay Bridge in 1973. It will replace an existing steel cantilever truss bridge built in 1927 that was found to be seismically inadequate. The new bridge consists of an orthotropic closed steel box girder superstructure, two 512 mm (20-1/8″) diameter main cables, reinforced concrete towers and gravity anchorages. The design has set a new standard in modern suspension bridge design in the United States, particularly with respect to seismic safely. Some of the key elements of the design discussed in this paper are the global design loading criteria for long span suspension bridges; design allowable stresses in main cable wire; state-of-the-art design detailing of critical welded connections; the finite element analysis approach for the box girder to determine the actual plate stresses and stress concentrations; and design of the reinforced concrete tower leg sections for enhanced ductile seismic performance.