Design of Kouchigawa Bridge on the Shin-Tomei Expressway - a Steel- Prestressed Concrete Composite Multiple-span Balanced Arch Bridge

A three-span composite balanced arch structure was adopted as the river-crossing section of the bridge, using a balanced truss cantilever erection method. The arch ribs were designed as prestressed concrete (PC) box girders and the stiffening girders were designed as steel box girders. PC box girders were also adopted on the approach spans. In order to improve driving comfort of passing traffic and minimize maintenance cost, the stiffening girders of the balanced arch are connected with the PC box girders of the approach spans without expansion joints. In order to increase the seismic resistance of the bridge, rigid connections were used at most joints between the substructures and superstructures, and between the vertical members and stiffening girders.