Civil Engineering Reference
In-Depth Information
Using Table A.20 of Appendix,
n
9
6
9.50 ft
c
9.50
8
12
8.833 ft
n
9.50
0.930
u
c
8.833
c
With reference to the figure given with Table A.20:
a
b
4
4
1.00
k
AB
4.81 by interpolation
(4.81)(3.64
10
6
)(4219)
(9.5)(12)
4.81
E
cc
I
c
H
K
c
648
10
6
in.- lb
C
AB
0.55 by interpolation
6.
Determine the torsional stiffness of the slab section (see Figure 17.10):
x
3
y
3
1
0.63
x
y
C
1
0.63
8
15
8
3
15
3
1700 in.
4
(9)(3.64
10
6
)(1700)
9
E
cs
C
K
t
2
1
c
2
2
3
3
15
(12)(22)
(12)(18)
1
307.3
10
6
psi
7.
Compute
K
ec
, the stiffness of the equivalent column:
K
c
K
t
K
c
K
t
(2
648.0)(2
307.3)
23
648.0
2
307.3
K
ec
416.9
10
6
in- lb
A summary of the stiffness values is shown in Figure 17.11.
Figure 17.10
