A Study on the Design Bending Monments of Wide Cantilever Slabs

Recently, steel-concrete composite bridges with two-girders, with long span slabs, have been regarded as one of the economical as well as durable bridge types. However, in Korea, there is little experience on the design and construction of this bridge system. In the design of long span slabs questions have been raised whether the current design provision is applicable in the respect of minimum thicknesses and bending moments. Also, there is a need for establishing a reasonable design method for long span slabs. In this study, 3-D finite element analyses were performed to derive design bending moment formulae for wide cantilever slabs. The proposed formulae were considered effects of the relative stiffness ratio and the front and middle axle loads. From the analytical studies, it was determined that the behavior, of wide cantilever slabs, was effected by the number of wheel loads as well as the stiffness of the supports. Also, design bending moment formulae, for cantilever slabs, in the current design specifications overestimate the negative bending moment at the supporting girder for wide cantilever slabs.