Scientific paper ID 2763 : 2025/3

Bridge structures in general are subjected to significant dynamic loads. These are impacts that change rapidly over time in location, magnitude, direction or direction, especially in the transitional areas at their connection with the earth-fill body. They cause significant accelerations and inertial forces, which must be taken into account even during the design.

According to their characteristics, dynamic loads can be divided into the following groups: mobile, seismic, wind, stationary periodic, short-term /impulse/, stationary impact, etc. For bridge structures, the first three groups of loads are of greatest importance.

In bridge structures, multiple or close natural frequencies are often obtained, to which, however, different natural vibration modes correspond. Therefore, the same dynamic, including seismic, load can excite several natural modes, in which the vibrations are superimposed on each other. This causes vibrations. In order to determine the most unfavorable direction for the various forces, they must be studied separately for a number of directions.

In this report, the influence of the dynamic load from rolling stock is studied, as partially imitating seismic effects that threaten the reliability of the transition areas at the connection between bridges and the earth-fill body, as the basis of the railway lines. In connection with improving the stability of the structures of the railway infrastructure facilities under increasing dynamic loads, a measurement of vibration acceleration and vibration displacement from the passing rolling stock in the transition area at the connection between a reinforced concrete bridge and the earth-fill body behind the abutment was carried out.