ABSTRACT
ABSTRACT: Bridges and viaducts for high speed trains are subject to demanding dynamic loads. In addition to the classical effect of the moving (single) load, much larger and potentially dangerous effects arise from dynamic resonance, for speeds above 200 km/h. The classical methods for evaluation of dynamic impact factors, reflected in the codes of practise existing until recently, do not cover this possibility of resonance. The design of such structures requires dynamic calculations which are the object of this paper.We discuss briefly availablemethods for dynamic analysis, aswell as the new codes IAPF [9] and Eurocode 1 for actions on bridges [10]. One of the key aspects which is desirable for the new lines is their qualification for interoperability, so that all possible present and future European high speed trains may use them [19]. The proposal for this is covered in [10, 9] through the new High Speed Load Model HSLM, whose background is discussed here. Finally, some results obtained by our group are presented for high speed traffic loads on bridges. These studies focus on the evaluation of the bridge-vehicle interaction in bridges and a discussion and proposal for dynamic uplift dynamic effects. These topics originate from issues in the application of the new regulations for high speed lines, and are oriented toward being of practical use to designers of railway bridges.
