Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 127

any dynamic factors. The characteristic value of the centrifugal force shall be
determined according to the following equations specified in EC1:

v 2
g r

V 2
127 r

Q tk ¼ ð f Q vk Þ ¼ ð f Q vk Þ ð 3 : 6 Þ

v 2
g r

V 2
127 r

q tk ¼ ð f q vk Þ ¼ ð f q vk Þ ð 3 : 7 Þ

where Q tk and q tk are characteristic values of the centrifugal forces in kN and
kN/m, respectively. Q vk and q vk are characteristic values of the vertical loads
(excluding any enhancement for dynamic effects) for Load Models 71, SW/
0, SW/2, and “unloaded train.” For HSLM, the characteristic value of the
centrifugal force should be determined using Load Model 71. f is a reduction
factor. v is the maximum speed in m/s. V is the maximum speed in km/h. g is
the acceleration due to gravity 9.81 m/s 2 . Finally, r is the radius of curvature
in m. In the case of a curve of varying radii, suitable mean values may be
taken for the value r .
The calculations shall be based on the specified maximum line speed at the
site. In the case of Load Model SW/2, an alternative maximum speed may be
assumed. For SW/2, a maximum speed of 80 km/h may be used. It is recom-
mended that the individual project specify an increased maximum line speed
at the site to take into account potential modifications to the infrastructure and
future rolling stock. For Load Model 71 (and where required Load Model
SW/0) and a maximum line speed at the site higher than 120 km/h, two cases
should be considered. In the first case, Load Model 71 (and where required
Load Model SW/0) with its dynamic factor and the centrifugal force for
V¼ 120 km/h according to Equations (3.6) and (3.7) with f¼ 1 should be
considered. While in the second case, Load Model 71 (and where required
Load Model SW/0) with its dynamic factor and the centrifugal force accord-
ing to Equations (3.6) and (3.7) for the maximum speed V specified should
also be considered, with a value for the reduction factor f given by Equa-
tion (3.8) . For Load Model 71 (and where required Load Model SW/0),
the reduction factor f is subject to a minimum value of 0.35 and is given by

r

2

1

V 120
1000

814
V +1

88
L f

:

f ¼ 1 : 75 ð 3 : 8 Þ

where L f is the influence length of the loaded part of the curved track on the
bridge, which is most unfavorable for the design of the structural element
under consideration in meters as detailed in EC1 [ 3.1 ] .