Civil Engineering Reference
In-Depth Information
2-1/2
"
85
"
5/8
"
2-1/2
"
20
"
FIGURE E7.1
A(y
b
−
I
o
=
y)
2
223,444 in.
4
,
I
g
=
+
191,406
+
32,038
=
I
c
y
A
=
42.5
(
5
/
8
)
3
2.5
(
20
)
3
[
+
]
r
c
y
=
=
4.67 in.,
12
[
20
(
2.50
)
+
42.5
(
5
/
8
)
]
223,444
45.0
=
4965 in.
3
,
S
g
=
n
ng
(
223,444
)
45.0
4965
n
ng
in.
3
,
S
n
=
=
n
ng
=
I
n
/I
g
(net-to-gross area ratio).
Weightofthegirder
=
153.1
(
490
/
144
)
=
521 lb/ft(46,900 lbtotalpergirder).
TABLE E7.2
Element
A
(in.
2
)
Ay
b
(in.
3
)
y
)
2
(in.
4
)
I
o
(in.
4
)
y
b
(in.)
y
b
−
y
(in.)
A
(
y
b
−
Top flange
50.00
88.75
4437.5
43.75
95,703
26.0
Web
53.13
45.00
2390.6
0
0
31,986
Bottom flange
50.00
1.25
62.5
−
43.75
95,703
26.0
153.13
6890.6
191,406
32,038
