Civil Engineering Reference
In-Depth Information
The calculation of net area is shown in Example 6.1.
Example 6.1
Member U1-L1 is connected with gusset plates to the bottom chord of
the truss in
Figure E6.1
by 7/8 in. diameter ASTM A325 bolts, as shown in
Figure E6.2. Determine the net area of the member if it is comprised of two
laced C 12
30 channels.
ForaC12
×
×
30 channel:
8.82 in.
2
A
=
t
w
=
0.51 in.
b
f
=
3.17 in.
t
f
=
0.50 in.
7.80 in.
2
Path A-B-D-E:
A
n
=
8.82
−
2
(
1
)(
0.51
)
=
3
2
/
4
(
2.5
)
]}
(
0.51
)
=
8.21 in.
2
Path A-B-C-D-E:
A
n
=
8.82
−{
3
(
1
)
−
2
[
3
2
/
4
(
2.5
)
]}
(
0.51
)
=
8.26 in.
2
Path A-B-C-E1:
A
n
=
8.82
−{
2
(
1
)
−
1
[
U1
U3
U4
27.25'
L2
L3
19.55
ft, typ.
L0
L1
156.40 ft
FIGURE E6.1
A1
A
B
T
12.0"
C
2.5"
D
D1
3.5"
E2
E1
E
5@ 3" = 1' - 3"
FIGURE E6.2
