Civil Engineering Reference
In-Depth Information
0003
L
2
m
2
w
s
1
¼
1
:
:
04
L
+0
:
3
:
=
75 + 0
5kN
0003
40
2
w
s
1
¼
1
:
75 + 0
:
04
40 + 0
:
¼
3
:
83
m
2
Weight of steel structure for part of bridge outside main trusses:
m
2
>
3
:
5kN
=
taken as 3
:
5kN
=
m
2
w
s
2
¼
1+0
:
03
L
kN
=
m
2
w
s
2
¼
1+0
:
03
40
¼
2
:
2kN
=
m
Weight of reinforced concrete decks and haunches:
w
s
¼
3
:
5
10
=
2+2
:
2
3
¼
24
:
1kN
=
m
Weight of finishing (assume weight of finishing is 1.75 kN/m
2
for parts
between sidewalks and 1.5 kN/m
2
for sidewalks):
w
F
¼
1
w
RC
¼
0
ð
:
2+0
:
01
Þ
25
6+ 0
ð
:
15 + 0
:
01
Þ
25
2
¼
39
:
5kN
=
:
75
6+1
:
5
2
¼
13
:
=
m
We can now calculate the total dead load acting on main trusses in the
longitudinal direction (see
Figure 4.176
)
as follows:
w
D
:
L
:
¼
24
5kN
:
1+39
:
5+13
:
5
¼
77
:
1kN
=
m
Live Loads
To determine the live loads acting on main trusses in the longitudinal dir-
ections, we can study different lateral sections through vehicles, distributed
loads, and sidewalks of Load Model 1 acting on the bridge, as shown in
Figure 4.177
. From the lateral section shown in
Figure 4.177
, we can find
that the maximum concentrated and distributed loads transferred to a main
truss are 450 kN and 45.65 kN/m, respectively, as shown in
Figure 4.178
.
We can also calculate the negative distributed reactions acting on a main
truss in the longitudinal by investigating the case of loading shown in
Figure 4.179
.
The negative concentrated and distributed loads acting on a
main truss are 7.5 kN and 2.45 kN/m, respectively, as shown in
Figure 4.180
. The calculated dead and live loads can be now used to
g
vk
= 77.1 kN/m
Figure 4.176 Dead loads acting on main trusses.
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