Civil Engineering Reference
In-Depth Information
P
L
C
D
B
A
h
p
(
h
e
+
h
p
)/2
V
e
V
e
P
e
b
t
P
e
FIGURE E5.14
Triangular portal frame.
Example 5.15
The forces in the end portal bracing system
(Figure E5.15)
of the through truss
span in Example 5.10 are required.
h
e
=
33.5 ft (in-plane height of the portal)
h
p
=
8.5 ft (in-plane height of the portal bracing system)
20.0
(spacing of trusses)
P
L
=
(
6
)
19.55
(
0.35
)/
2
b
t
=
20.4 kips (top lateral truss wind force reactions
transferred to the end portal frame)
R
e
=
=
20.4
[
(
42.0
)/
2
]
/
20
=
21.4 kips (additional compression in the end post
due to portal action)
P
L
C
D
8.5'
B
A
5.0'
33.5'
M
e
M
e
H
e
H
e
R
e
20.0'
R
e
FIGURE E5.15
Braced triangular portal frame.
