Civil Engineering Reference
In-Depth Information
The perimeter of the steel section is
u
a
1140 mm. Assuming a trans-
mission length of 640 mm, twice the least lateral dimension, Equation
5.34 gives
=
τ
Ed
=
N
Ed,c
/
u
a
V
=
201/(1.14
×
640)
=
0.27 N/mm
2
This is less than
τ
Rd
, Equation 5.35, so local bond stress is not excessive,
and shear connection is not required.
This completes the validation for this column length, provided that
analysis for lateral loading (Section 5.9) confirms the assumption that it is
all transferred by the floors to the end walls and the central core.
5.8
Example (continued): internal column
A typical internal column between level 0 and level 1 is now designed,
for the arrangement of variable loading shown in Fig. 5.9. Full permanent
load acts on all of the beams. Variable load acts on all beams at levels 2
to 9, but not on beams AD and CG, as this increases the single-curvature
bending moment in length CD of the column. Any rotational restraint
from point E, at basement level, is neglected.
In Section 5.7.1, the live-load reduction factor was found to be
α
n
0.767. This reduces the design ultimate load on each beam from
60.9 kN/m (Table 4.4) to 52.2 kN/m. This reduction is not made for the
beams that cause bending in the column, so the beam loadings for the
global analysis are as shown in Fig. 5.19.
=
Figure 5.19
Loadings and major-axis bending moments for an
internal column
