L is the determinant length U [m] in accordance with 6.4.3
F.2 General design method
(1)P The calculation, in general a stress range verification, shall be carried out according to ENV 1992, ENV 1993 and ENV 1994.
(2)P As an example for steel bridges the safety verification shall be carried out by ensuring that the following condition is satisfied:
YFf is the partial safety factor for fatigue loading, yR = 1,00.
X is the factor which takes account of the service traffic on the bridge and the span of the member.
is the dynamic factor (see 6.4).
Ao71 is the stress range due to the Load Model 71 being placed in the most unfavourable position for the element under consideration.
Aoc is the reference value of the fatigue strength (see ENV 1993) YMf is the partial safety factor for fatigue strength (see ENV 1993)
The fatigue assessment has to be carried out on the basis of the traffic mixes, "usual traffic" or "traffic with 250 kN-axles", depending on whether the structure carries standard traffic mix or predominantly heavy freight traffic. Details of the service trains and traffic mixes to consider are given below.
(I) Standard traffic with axles s 225kN
Type I Locomotive-hauled passenger train
ZO ■ 6630kN V « 200km/h L « 262.10m q « 25.3kN/m'
6 x 225KN 4 x 110kN
Was this article helpful?