Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 145

into account (e.g., with reference to a safety distance between piers and the
edge of the carriageway), the magnitude and location of vehicular collision
forces and also the limit states should be considered. For stiff piers, the min-
imum values recommended in EC1 [ 3.1 ] are an impact force of 1000 kN in
the direction of vehicle travel or 500 kN perpendicular to that direction
with height above the level of adjacent ground surface equal to 1.25 m.
3.5.3.3 Collision Forces on Decks
Vehicle collision forces on bridge decks should also be specified as recom-
mended in EC1. The National Annex may define the collision force on
decks, possibly in relation to vertical clearance and other forms of protection.
Collision loads on bridge decks and other structural components over roads
may vary widely depending on structural and nonstructural parameters and
their conditions of applicability. The possibility of collision by vehicles hav-
ing an abnormal or illegal height may have to be envisaged and a crane
swinging up while a vehicle is moving. Preventive or protective measures
may be introduced as an alternative to designing for collision forces.
3.5.3.4 Actions from Vehicles on the Bridge
Collision forces from vehicles on footways and cycle tracks on road bridges
are also covered by EC1 [ 3.1 ] . If a safety barrier of an appropriate contain-
ment level is provided, wheel or vehicle loading beyond this protection need
not be taken into account. Where the protection mentioned is provided,
one accidental axle load corresponding to a Q2 Q 2k should be so placed
and oriented on the unprotected parts of the deck so as to give the most
adverse effect adjacent to the safety barrier as shown in Figure 3.16 . This axle
load should not be taken into account simultaneously with any other vari-
able load on the deck. A single wheel alone should be taken into account if
geometric constraints make a two-wheel arrangement impossible.
3.5.3.5 Collision Forces on Curbs
The action from vehicle collision with curbs or pavement upstands should
be taken as a lateral force equal to 100 kN acting at a depth of 0.05 m below
the top of the curb, following the guidelines of EC1. This force should be
considered as acting on a line 0.5 m long and is transmitted by the curbs to
the structural members supporting them. In rigid structural members, the
load should be assumed to have an angle of dispersal of 45 . When unfavor-
able, a vertical traffic load acting simultaneously with the collision force
equal to 0.75 a Q1 Q 1k (see Figure 3.17 ) should be taken into account.