Civil Engineering Reference
In-Depth Information
determine the values shown. The use of Table 5.1 f or determining maximum bending
moments due to Cooper's E80 load is outlined in Examples 5.1 and 5.2.
Example 5.1
Determine the maximum bending moment per rail for Cooper's E80 load on
a 60 ft long deck plate girder (DPG) span. The moment at the center, C, is
assumed to be near the maximum bending moment in both location and
magnitude.
A review of the Cooper's load configuration indicates that the maximum
moment will likely occur under axles, NP
=
3, 4, 5, 12, 13, or 14 ( Figure E5.1).
With NP
=
3 (Cooper's load configuration wheel number 3)
From Table 5.1:
x 1 = (S 1 ) 3 =
13 ft
since x 1
L/ 2
30 ft; N1
=
1
support B is (L/ 2
+
x 1 ) =
30
+
13
=
43 ft from N1
since (S 1 ) 8 =
43 ft, NL
=
8 and is over support B
xL
0
NE is the last wheel on the span and is equal to NL
=
43-43
=
1
=
7 when NL is over
support B
M ( NL 1 ) ,N1 + P N1,NE (xL)
60
M 7,1 + P 1,7 (xL)
60
M B
L
R B =
=
=
5702
+
232 ( 0 )
60
=
=
95.03 kips,
M ( NP−1 ) ,N1 =
M 2,1
M C =
R B (L/ 2 )
R B (L/ 2 )
=
95.03 ( 30 )
460
=
2391 ft-kips.
©
NP
NL
N1
C
A
B
x 1
xL
L /2
L /2
FIGURE E5.1
 
 
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