Annex F (normative)
Basis for the fatigue assessment of railway structures F.1 Assumptions for fatigue actions
The dynamic factors fa and fa which are applied to the static Load Model 71, when clause 6.4.3 applies, represent the extreme loading case to be taken into account for detailing bridge members. These factors would be unduly onerous if they were applied to the service trains used for making an assessment of fatigue damage. To take account of the average effect over the assumed 100 years life of the structure, the dynamic enhancement for each service train is reduced to where <p' and <p" are defined below in equations (F.2) and (F.3). (These equations-are simplified forms of equations (E.3) and (E.5) which are sufficiently accurate for the purpose of calculating fatigue damage):
Was this article helpful?