Civil Engineering Reference
In-Depth Information
Bridge type
I
II
III
d
d tot
d
tot
tot
a)
b
b
b
d
tot
d
d
tot
tot
b)
b
b
b
d
tot
A ref, x = d tot L
C fx,0
Trusses separately
2.4
2.0
1.8
1.5
a) Construction phase or open parapets
(more than 50% open)
b) With parapets or barrier or traffic
1.3
1.0
0.5
0
b/d tot
0 1
2
3
4
5
6
7
8
9
10
11 12
Figure 3.13 Force coefficient for bridges, c fx,0 , specified in EC1 [ 3.1 ] .
1
2 rv b CA ref , x
F w ¼
ð 3
:
13 Þ
where v b is the basic wind speed, C is the wind load factor, A ref, x is the
reference area, r is the density of air, which is reasonably assumed as
1.25 kg/m 3 .
14 Þ
The fundamental value of the basic wind velocity, v b,0 , is the character-
istic 10 min mean wind velocity, irrespective of wind direction and time of
year, at 10 m above ground level in open country terrainwith low vegetation
v b ¼ c dir c season v b , 0
ð 3
:
 
 
 
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