Introduction - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 22

concluded that the geometrically and/or materially nonlinear behavior of
horizontally curved ridges was not fully understood. The study has also out-
lined the shortcomings in the previously published experimental investiga-
tions comprising stability issues related to curved box and I-girder bridges
during construction; effects of ties, bracing, and web stiffeners on the distor-
tional behavior of the bridges during construction; field experimental pro-
grams to measure internal forces and deformations in the main girders and
the bracing during construction; experiments demonstrating local and
lateral-torsional buckling; experiments demonstrating the limit states in a
transversely and/or longitudinally stiffened web; experiments addressing
the effective width of the concrete slab in both curved box and I-girders;
and cost-effective construction methods and erection guidelines that incor-
porate the experience of steel fabricators and erectors.
Padgett and DesRoches [ 1.35 ] performed a nonlinear 3D time history
analysis for typical multispan simply supported and multispan continuous
steel girder bridges to evaluate the effectiveness of various retrofit strategies.
The influence of using restrainer cables, steel jackets, shear keys, and elasto-
meric isolation bearings on the variability and peak longitudinal and trans-
verse responses of critical components in the bridges was investigated by the
authors. The authors concluded that different retrofit measures may be more
effective for each class of bridges. The restrainer cables are effective for the
multispan simply supported bridge, shear keys improve the transverse bear-
ing response in the multispan continuous bridge, and elastomeric bearings
improve the response of the vulnerable columns in both bridges. The study
[ 1.35 ] has also shown that while a retrofit may have a positive influence on
the targeted component, other critical components may be unaffected or
negatively impacted. Shoukry et al. [ 1.36 ] investigated the long-term
sensor-based monitoring of the Star City Bridge in Morgantown, WV,
USA, which was a steel girder bridge designed according to Load and Resis-
tance Factor Design (LRFD) of the American Association of State Highway
and Transportation Officials (AASHTO) [ 1.37 ] . The bridge had a length of
306 m over four spans. Overall, the study aimed to demonstrate the long-
term performance of existing lightweight bridge decks. The bridge was
heavily instrumented with over 700 sensors that recorded the response of
the main superstructure elements to various loading parameters. The authors
have recorded data to monitor and evaluate the performance of the bridge
since construction over a 4-year period. The authors have shown that the
expansion and contraction of the superstructure at one end contributed
to the relief of environmentally induced internal stresses in the longitudinal