ABSTRACT
The paper presents the research methods and results of dynamic load testing of dozen bridges before opening for service to trains running with speed up to 200km/h. All presented bridges had the same design -steel beams encased in concrete. The tests included passages at different speeds of a special test train consisting of two locomotives and four passenger wagons placed between them. The measurements included vertical displacements of the spans, acceleration of the bridge deck vibrations and the speed of the train. The analysis of the test results was carried out for forced and free bridge vibrations. In the case of forced vibrations, the relationships between the extreme amplitudes of displacements and accelerations and the speed of the spe-cial train were determined. In the case of free vibrations, the vibration frequencies were determined.
