The targeted and accurate determination of dynamic properties of railroad bridges (natural frequencies, damping) is an important contribution to the evaluation and recalculation of critical existing structures. Especially with regard to changed boundary conditions (e.g. new train types, higher control speeds) it becomes necessary to re-evaluate the bridge stock. In addition to the determination of natural frequencies and shapes, the exact metrological determination of damping is a challenging issue, since the methods of excitation currently used in practice (e.g. ambient, sandbag, train crossing) are subject to imponderables which can lead to large scatter in the results. Especially for structures with small span width and high stiffness it is difficult to determine the damping parameters with sufficient accuracy.
Based on this problem, AIT and the project partners worked together to reliably determine the relevant dynamic parameters. For this purpose, in addition to the classical excitation methods, various exciters (including MoSeS and Longstrokeshaker) are used in a large-scale measurement campaign on a large number of structures in order to specifically control the excitation forces introduced into the structures. The results of the project will be used in the revision of guidelines for the dynamic measurement and recalculation of railroad bridges.
REVOTEC, TU Wien Institut für Tragkonstruktionen Stahlbau
ÖBB Infrastruktur AG