The Impact of Construction Structure Material on the Dynamic Response of Railway Bridges Under Passing of High-speed Trains

Abstract With the development of life and its requirements increasing, it has become necessary to find means that reduce the time to meet them, and one of these means is high-speed trains. Many previous studies have dealt with different properties affecting the dynamic behavior of railway bridges. In this research, the effect of changing the structural material of part of the main bridge structure on its dynamic behavior were be studied. Two types of bridges were studied. The first is the steel-girder bridge, and the second is the polygonal concrete bridge. The bridge modeling was done through the program SAP2000 and the structural analysis of the study model was done by using the finite element method. Material and mechanical properties from laboratory experiments were used for previous studies. The results for the two dynamic behavior parameters that were tested showed larger values in the polygonal model of the bridge. It increases in the steel beam model by 59% for vertical displacement and by 45% for vertical acceleration. The vertical displacement values were within the limits of the international standard L/600, and the vertical acceleration was within the limits of the European standard 3.5 g. The best design for each speed should be determined by conducting more study, which should include testing models at various speeds.