Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 28

buckling analysis were briefly reviewed. The authors proposed a new
criterion for a beam-column member based on the axial-flexural interaction
equation in combination with the classical tangent modulus theory and the
column-strength curve. The study has shown that the proposed criterion for
a beam-column is appropriate to determine the collapse loads of steel cable-
stayed bridges. It was also concluded that the inelastic buckling analysis using
the proposed criterion for a beam-column can substitute complex nonlinear
inelastic analysis in estimating the collapse load of a steel cable-stayed bridge.
Shifferaw and Fanous [ 1.51 ] investigated fatigue-crack formation in the
web-gap region of multigirder steel bridges. The authors have shown that
the region has been a common occurrence of fatigue-crack formation
due to differential deflections between girders resulting in diaphragm forces
that subject the web-gap to out-of-plane distortion. The study investigated
the behavior of web-gap distortion of a skewed multigirder steel bridge
through field testing and finite element analyses. The study also investigated
different retrofit methods that include the provision of a connection plate
between the stiffener and the girder top flange, loosening of the bolts con-
necting the cross bracing to the stiffener, and supplementing a stiffener plate
opposite to the original stiffener side. The study has shown that the connec-
tion plate addition and loosening of bolts alternatives were effective in
reducing induced strains and stresses in the web-gap region. An inverse rela-
tionship between web-gap height and induced strains and stresses with the
shortest web-gap height resulting in the highest strains due to increased
bending by diaphragm forces in the web was also shown. The authors
concluded that expressions developed to relate vertical stresses and relative
out-of-plane displacements combined with measurements of out-of-plane
displacements by transducers can be utilized for prediction of induced stres-
ses at other critical web-gap regions of the bridge and at critical locations in
the web gaps of similar bridges.
Postrehabilitation assessment of existing bridges is a current research
topic. Cavadas et al. [ 1.52 ] presented the postrehabilitation assessment of
the Eiffel Bridge, which is a centenary double-deck bridge located in
Portugal. Recently, the bridge was rehabilitated involving the replacement
of the top deck, the strengthening of the top chords, and the replacement of
the support bearings. After the rehabilitation, a load test and an environmen-
tal test were carried out in order to analyze the bridge behavior and the
live-load distribution for the new structural conditions, to evaluate the effec-
tiveness of the chords' strengthening, and to establish the new baseline con-
dition for future structural assessments. The field results were augmented by