A Study on the Minimum Thickness of Long Span Decks

Recently, the steel-concrete composite two-girders bridges, which have PSC long span decks, have been regarded as one of the economical as well as durable bridge types. Usually, prestressing forces are introduced in the transverse direction of the long span deck. However, for the design of long span deck a question is raised whether the current design provision is applicable in the respect of minimum thicknesses and bending moments. In this study, 3-D finite element analyses were performed to compare actually required thickness of the long span deck with the code-specified minimum thickness. Also, full-scale static tests were conducted to examine the ultimate and serviceability behaviors of long span decks for the several thicknesses and spans. From the analytical and the experimental studies, it is concluded that the code-specified minimum thicknesses can be reduced at least for the long span decks. Finally, the effects of front and middle wheel loads or the deck behavior were investigated, which could induce unsafe characteristics especially for the long span decks over 10m.