FATIGUE REAL SCALE TEST COMPARISON WITH ACTUAL BRIDGE MONITORING

Abstract

In railway bridges, special attention needs to be paid to the interaction between the railway track and the bridge. Forces occur in the rails, as well as in the deck and the bearings of the bridge. These forces result in additional stresses, which need to be kept sufficiently low. Peak stresses due to e.g., temperature variations and bridge deck bending are especially to be feared at the bridge/abutment transition. Special rail fastening systems may be used to limit these additional stresses. Real scale tests were performed to verify the behavior of the track and the bridge equipped with such modified fasteners, which are designed to limit the transfer of longitudinal forces to the bridge. Based on the data from these tests, a detailed finite element model is constructed in this research paper. In contrast to the generally accepted modeling approach prescribed by international norms such as Eurocode NBN EN 1991-2 and UIC Code 774-3R, this research is performed, assuming the fact that the behavior due to track-bridge interaction can be simulated by a rail model supported by springs, i.e., without the need to model the actual bridge structure in detail. The results of these finite element model simulations are compared with data of a long-term monitoring program using strain gauges on all elements of the rails and support structure of an actual railway bridge in Belgium.