A methodology for the assessment of the train running safety on bridges

xii proposed method for the lateral displacements and y w rotations of the wheelset are compared with those obtained with a semi-analytical model de scribed in the literature. In the last application, an experimental test conducted in the rolling stock test plant of the Railway Technical Research Institute in Japan, in which a f ull scale railway vehicle runs over a track with vertical and lateral deviations is reproduced numerically. The results obtained with the proposed method are compared with the experimental resu ts and also with the results obtained using the software DIASTARS. Finally, a study regarding the running safety of a high-speed train moving over a viaduct under seismic conditions is conducted using the dev eloped train-structure interaction method. The studied viaduct is based on an existing flyover type structure of the Portuguese railway network, while the vehicle consists of a Japanese S hinkansen high-speed train. The seismic action is represented in terms of artificial accele rograms generated from the elastic spectra described in EN 1998-1, while the irregularity prof iles are generated based on analytical power spectral density functions. Since no significant no nlinear behavior is likely to be exhibited in the columns for the levels of seismicity considered in this work, all the analysis are performed in the elastic domain with a reduction in the stiff ness of the columns to account for the concrete cracking. The running safety analysis of the railwa y vehicle running over the viaduct is assessed based on four derailment criteria, being t he influence of the seismic intensity level, the vehicle running speed and the track quality on the running safety evaluated separately. At the end, all the information obtained in the dynamic an alyses is condensed in the so-called running safety charts, which consist in the global envelope f ach analyzed safety criteria as function of the running speed of the vehicle and the seismic intensity level.