A pin-connected skeleton frame, shown in Fig. 2.1, was analyzed under AASHTO
loads. This analysis was compared to the deck model subject to the same loads. As-built
dimensions and section properties from the Fruita Bridge were used. Because it was
desired to investigate the problem using software tools that were readily available to
practicing engineers, RISA-3D software (RISA 2002) was used for both analyses.
RISA-3D is exemplary of readily available software that includes both frame elements
and plate/shell elements.
Figures 2.2 and 2.3 illustrate the superimposed vertical dead loads (gravity loads)
and their effect, respectively, for the skeleton structure. Live load was not included in the
analysis.