Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 128

3.4.2.2 Nosing Force
The nosing (lateral shock) force shall be taken as a concentrated force acting
horizontally, at the top of the rails, perpendicular to the centerline of the
track. It shall be applied on both straight track and curved track. According
to EC1 [ 3.1 ] , the characteristic value of the nosing force shall be taken as
Q sk ¼ 100 kN. It shall not be multiplied by any other factor. The nosing
force shall always be combined with a vertical traffic load.

3.4.2.3 Traction and Braking Forces
Traction and braking forces act at the top of the rails in the longitudinal
direction of the track. According to EC1, the forces shall be considered
as uniformly distributed over the corresponding influence length L a,b for
traction and braking effects for the structural element considered. The direc-
tion of the traction and braking forces shall take account of the permitted
direction(s) of travel on each track. The characteristic values of traction
and braking forces given in EC1 [ 3.1 ] are as follows:

Traction force : Q lak ¼ 33 kN ð = m ÞL a , b ðÞ 1000 k ðÞ

ð 3 : 9 Þ

For Load Models 71,SW = 0,SW = 2, and HSLM

Braking force : Q lbk ¼ 20 kN ð = m ÞL a , b ðÞ 6000 k ðÞ

ð 3 : 10 Þ

For Load Models 71,SW = 0,SW = 2, and HSLM

Q lbk ¼ 35 kN

ð ÞL a , b ðÞ
For Load Model SW

=

ð 3 : 11 Þ

= 2

The characteristic values of traction and braking forces shall not be mul-
tiplied by any other factor.
EC1 [ 3.1 ] specifies that for Load Models SW/0 and SW/2, traction and
braking forces need only to be applied to those parts of the bridge that are
loaded according to Figure 3.2 and Table 3.1 . Traction and braking may be
neglected for the Load Model “unloaded train.” These characteristic values
are applicable to all types of track construction, e.g., continuous welded rails
or jointed rails, with or without expansion devices. The earlier-mentioned
traction and braking forces for Load Models 71 and SW/0 should be mul-
tiplied by the factor a in accordance with the requirements of Section 3.3.1 ,
as specified in EC1 [ 3.1 ] . For loaded lengths greater than 300 m, additional
requirements for taking into account the effects of braking should be spec-
ified. For lines carrying special traffic (e.g., restricted to high-speed passenger
traffic), the traction and braking forces may be taken as equal to 25% of the
sum of the axle loads (real train) acting on the influence length of the action