Approximate Analysis of Concrete Box Girder Bridges

The purpose of this paper is to show that the actual threedimensional behavior of a box girder bridge as predicted by a folded plate, finite strip, or finite element analysis can be approximated by using some simple membrane equations in conjunction with a plane frame analysis. This is a useful method since virtually all structural engineers have access to a plane frame computer program, while many have neither the access nor the inclination to use more sophisticated programs. In particular, the method allows the reinforcing and prestressing to be proportioned for transverse flexure, as well as the stirrups to be proportioned for longitudinal shear and torsion in single‐celled precast concrete segmental box girder bridges. Three numerical examples illustrate how the method may be applied to practical problems.