Civil Engineering Reference
In-Depth Information
d
=
(
25
/
30
)
15
=
12.50
e
=
60
/
4
=
15.00
f
=
(
21
/
30
)
15
=
10.50
g
=
(
16
/
30
)
15
=
8.00
=
(
10
/
30
)
15
=
5.00
h
i
=
(
5
/
30
)
15
=
2.50
M
C
=
20
(
3.50
)
+
40
(
7.50
+
10.00
+
12.50
+
15.00
)
+
26
(
10.50
+
8.00
+
5.00
+
2.50
)
=
2546 ft-kips.
Example 5.4
Determine the bending moment per rail at location C under axle
NP
3of
the Cooper's E80 load on a 60 ft long through plate girder span with a floor
system comprising floorbeams and 20 ft long stringers.
The influence line for bending moments at location C is shown in
Figure E5.4.
The ordinates of the influence lines are
=
a
=
(
7
/
20
)
13.33
=
4.67
b
=
(
15
/
20
)
13.33
=
10.00
5′
6′
8
′
5
′
5
′
9
′
5
′
5′
40 k
40 k
40 k
40 k
20 k
26 k
26 k
26 k
26 k
c
d
e
b
f
h
a
i
g
C
13
′
B
A
5
′
20
′
30′
30′
FIGURE E5.4
