Design method of floor system in cable-stayed composite 2 girder bridges

Masatugu NAGAI

This paper proposes the design method of the floor system in cable-stayed composite 2 girder

bridges. A 3D finite element analysis is carried out, in which a concrete slab and steel girder are

modeled by solid and shell elements, respectively. In the analysis, the width of girder and the

distance of the cross beam are chosen as design parameters. The obtained results are compared

with those from the formula stipulated in Japan Highway Bridge Specifications (hereafter we call

JHBS) and the formula proposed by Matsui etcc.

The followings are summaries obtained from this study.

(1) For evaluating the longitudinal bending moment in the concrete slab under dead and live loads,

the formula stipulated in JHBS can be used.

(2) For evaluating the transverse bending moment in the concrete slab under live load, the formula

stipulated in JHBS cab be used.

(3) For evaluating the stress resultants in the cross beam, a simply supported beam model under

vehicle loads is used. A 60% of the obtained stress resultants from above beam model should be

used for the design. On evaluating the bending stress, the effective width stipulated in JHBS

can be used.