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stress for the design dead and live loads. After the design load was applied, the
live load was increased until the bridge model collapses. It was shown that the
collapse process differed depending on live-load distribution and span length
ratio. It was concluded that the investigation clarified the collapse process,
buckling strength, and influences of live-load distribution and the span ratio
imental investigation to determine the stress concentration factor and its sto-
chastic characteristics for a typical welded steel bridge T-joint. The study
reported a test on a full-scale segment model, which had the same profile
as an existing railway beam section of the suspension Tsing Ma Bridge.
The test had also the geometric dimension and material property as well
as weld details. Strain gauges were fitted on the web and flanges and the
hot spot strain at the weld toe is determined by a linear regression method.
The stress concentration factor was calculated as the ratio between the hot
spot strain and the nominal strain. The tests were carried out under different
moving load conditions. It was shown that the stress concentration factor for
the welded steel bridge T-joint conformed to a normal distribution.
A current research topic on steel bridges is the investigation of the struc-
tural behavior of the bridges under different fire conditions. Zaforteza and
ges by developing a 3D numerical model for a typical bridge of 12.20 m span
length. A parametric study was performed considering different axial
restraints of the bridge deck, different types of structural steel for the girders,
different constitutive models for carbon steel, different live loads, and differ-
ent fire loads. The numerical study showed that restraint to deck expansion
coming from an adjacent span or abutment should be considered in numer-
ical models. Also, times to collapse were very small when the bridge girders
are built with carbon steel (between 8.5 and 18 min), but they can almost
double if stainless steel is used for the girders. The authors recommended
that stainless steel be used as a construction material for girder bridges in a
high fire-risk situation. It was also concluded that the methodology devel-
oped in the study and the results obtained can be useful for researchers and
practitioners interested in developing and applying a performance-based
approach for the design of bridges against fire.
Structural health monitoring of steel bridges is a recent research topic for
evaluating bridge condition and safety. Measured strain data from a structural
health monitoring system can be used to assess the status of fatigue of steel
bridges, which is a common form of damage in this form of construction.
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