Lateral Distribution of Live Loads on Highway Bridges

Abstract

AASHTO specifications give a load fraction based on only two major variables that affect load distribution on highway bridges. For more economical design, a refinement of the AASHTO values is needed. In this paper, the processes for beam‐and‐slab and box‐girder bridge systems are shown. It is concluded that to make an economical design of a long bridge of moderate span, the accuracy of the transverse load distribution is a key factor. The finite element modeling methods for finding very accurate load distribution normally cannot be used early enough to help the designer at the beginning of the design process. For a multibox bridge, cross‐sectional transverse influence lines can always be developed with relatively short calculations for load distribution and torque.