Civil Engineering Reference
In-Depth Information
Reactions from stringers at edges due to dead loads
¼
77
:
5
=
2
¼
38
:
75 kN
m
Assuming the cross girders are simply supported by the main plate girders,
we find that the maximum shear force and bending moment due to dead
loads on an intermediate cross girder (see
Figure 4.171
)
are as follows:
Q
D
:
L
:
¼
208
Own weight of cross girder
¼
3
:
0kN
=
75 kN
M
D
:
L
:
¼
334 kNm
:
Live Loads
To determine the worst cases of loading on an intermediate cross girder due
to live loads, we can study different longitudinal sections through vehicles,
distributed loads, and sidewalks of Load Model 1 acting on the bridge, as
shown in
Figure 4.172
. From the different sections, we can find that the max-
imumconcentrated and distributed loads transferred to the intermediate cross
girder are as shown in
Figure 4.172
. The case of loading for the evaluation of
maximum positive bending moment due to live loads on an intermediate
cross girder can be studied, as shown in
Figure 4.172
.
The case of loading
is that the larger concentrated load from vehicles transferred is located at
the centerline (midspan) of an intermediate cross girder, with maximum
bending moment located at midspan as shown in
Figure 4.172
.
The maxi-
mum positive bending moment is calculated as follows:
2.5 kN/m
9 kN/m
5 m
5 m
264
264
176
176
88
45 kN/m
12.5
12.5 kN/
m
A
B
100
150
a
0.5
0.5
1.2
1.2
100
150
2 m
1.0
2
2
2.5
2
1.0
1.0
0.5
0.5
0.5
5 m
5 m
683.3 kN
552.2 kN
3.8
3.8
Figure 4.172 Case of loading for maximum positive bending moment from live loads
acting on an intermediate cross girder.
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