Fatigue life of concrete bridges under consideration of increasing traffic loads

Demands of bridge structures and their components by traffic loads are affected by many different parameters. Increasing traffic loads leads to higher fatigue stresses. Hereby, the effects on the stresses of the main load-bearing structure depend on the load models representing weight and the ratio of the load model length to the bearing distance of the superstructure. The different effects of varied load models are shown by opposing their influence lines. Axle loads and axle spacing are of vital importance to several components of the bridge structure. The consideration of more than one load cycle for each load model is relevant to local fatigue verifications.