Civil Engineering Reference
In-Depth Information
×
(
1
/
2
)
in. lacing bars at 30.6
◦
to horizontal:
Check design of 4 in.
6.5
2
11
2
+
12.8
40
t
lb
≥
=
=
0.32 in. OK
40
PF
y
150
F
all
≥
550
(
50
)
150
(
22.9
)
≥
V
=
0.025
P
=
0.025
(
550
)
=
13.8
≥
8.0 kips OK
V
2 cos 30.6
◦
13.8
2 cos 30.6
◦
P
lb
=
=
=
8.0 kips
0.166
(K)L
lb
r
lb
0.166
(
1.0
)
12.8
0.29
t
lb
0.166
(
1.0
)
12.8
0.29
(
0.5
)
F
all
=
30
−
=
30
−
=
30
−
=
30
−
14.7
=
15.3 ksi
P
all
=
(
15.3
)(
4
)(
0.5
)
=
30.6 kips
>
8.0 kips OK.
Check design of the main member with lacing bars at 30.6
◦
to horizontal:
L
p
/r
p
=
40 OK (length of the main member element
(channel) between lacing bar connections)
2
(
6.5
)/
0.867
=
15
≤
L
p
r
p
=
2
3
(
56.7
)
≤
15
≤
37.8 OK.
Design of the battened section
Compression member: 2
−
C
15
×
50 channels battened
6
2
in.backtobackwith6 in.
×
(
1
/
2
)
in.battenplatesasshowninFigureE6.6
50 channel and battened member section properties and allowable
compression force (675 kips) are same as that for the laced section design.
C
15
×
12"
15"
1-1/2"
11"
11"
14"
FIGURE E6.6
