Civil Engineering Reference
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reduction factor due to column buckling, and
r
is the reduction factor due to
plate buckling.
3.8.5.6 Verification
Member verification for uniaxial bending should be performed, according
N
Ed
f
y
A
eff
g
M0
+
M
Ed
+
N
Ed
e
N
f
y
W
eff
g
M0
1
¼
1
:
0
ð
3
:
68
Þ
where
A
eff
is the effective cross-sectional area,
e
N
is the shift in the position
of neutral axis,
M
Ed
is the design bending moment,
N
Ed
is the design axial
force,
W
eff
is the effective elastic section modulus, and
g
M0
is the partial
factor.
3.8.6 Behavior of Steel-Concrete Composite Plate Girders
Steel-concrete composite constructions offer many advantages including
high strength, full usage of materials, high stiffness and ductility, toughness
against seismic loads, and significant savings in construction time. In addition
to the aforementioned advantages, steel-concrete composite constructions
are gaining popularity due to the higher fire resistance compared to the con-
ventional steel constructions that require additional protection against fire.
Mainly in highway bridges, it is very common to benefit from the thick con-
crete deck on top of the floor beams (see Figure 1.21) and join them together
using shear connectors to ensure that the two components act together in
resisting traffic loads. Steel is known for its higher tensile resistance, while
concrete is known for its higher compressive resistance. Therefore, joining
the two components leads to the aforementioned benefits. In addition, steel
parts are thin-walled structures, which make it vulnerable to local and overall
buckling failure modes. The presence of a concrete deck on top of the steel
beams eliminates lateral torsional buckling and local buckling of the top
flange of the steel girders.
3.8.6.1 Effective Width of Flanges for Shear Lag
that allowance shall be made for the flexibility of steel or concrete flanges
affected by shear in their plane (shear lag) either by means of rigorous analysis
or by using an effective width of flange. The effective width of concrete
flanges should be determined such that when elastic global analysis is used,
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