Approximate and refined analysis methods - Computational Analysis and Design of Bridge Structures - page 22

(a)
(b)
(c)
Figure 2.6 Beam-slab bridges: (a) steel composite; (b) cast-in-place concrete; (c) precast
concrete.
(a) (b) (c)
Figure 2.7 Box-girder bridges: (a) rectangular attached multicell bridge; (b) detached
multicell box girder bridge; (c) trapezoidal attached multicell bridge.
bridges have the advantage of high torsional stiffness. Load distribution of a
box girder bridge, with its strong torsional stiffness, is usually more uniform
across the bridge width than that of an I-type beam-slab bridge with the
same span length and width.
Figure 2.7 shows some box girder bridges as examples. Figure 2.7a shows
a void slab with large attached cells (over 60% void ratio). Figure 2.7b is a
detached multicell box girder bridge. Figure 2.7c is a void slab with inclined
webs on the sides. If a single cell is used for this type of bridges, distortion
should be considered in the analysis.