Urban bridges studies on dynamic impacts from urban rolling stock

The article is dedicated to the actual dynamic impact study of rolling stock on urban bridges. The requirements for recording the dynamic impact specified in domestic and foreign regulatory documents are considered. Using a mobile measuring complex, the results of which determine the natural frequencies of vertical, horizontal transverse, and horizontal longitudinal vibrations. The technique used in the experiment allows us to obtain initial data for the dynamic calculation of structures, to clarify the real rolling stock dynamics depending on the state of the rail track on the bridge. Urban rolling stock is a relevant and necessary type of public transport that meets modern city requirements. The bridge crossings construction will ensure the connection of the urban areas separated by obstacles into a single network. When designing such structures, it is important to take into account the effects of actual dynamic coercitive forces. The dynamics study allows, on the one hand, to reasonably set the dynamic loads impact on bridges, on the other hand, to diagnose the structures state by dynamic parameters. In this work, using a specialized mobile measuring complex, the authors measured the oscillation parameters on moving vehicles. As a conducted experimental studies result, a methodology for determining the dynamic characteristics of a moving load and directly urban bridges has been demonstrated. As a result of the conducted experimental studies, it can be concluded that the proposed method allows obtaining initial data for the dynamic analysis of structures for the transport load. In addition, fixing the transport load dynamic impact during operation allows you to clarify the real rolling stock dynamics, depending on the state of the rail track on the bridge.