Feasibility of increasing train speed in existing railway concrete slab deck bridges

Increasing the train speed in railway networks is the most important factors in improving the fields of attracting more passengers and cargo than other transportation modes. The construction of new railway structures with the aim of increasing the speed of trains requires a lot of money. Therefore, the purpose of this study is to investigate the possibility of increasing the speed train using a low-cost method compared to the construction of new structures, such as changing the conditions of bridge bearings in existing concrete slab deck bridges. First, a 3D finite element model of the bridge and the train was created by considering the interaction of the track and the train, and it was validated based on the results of a valid field test. Then, the effect of increasing the speed of the train on the results of the vertical displacement and vertical acceleration of the bridge deck and the vertical acceleration of the train car body under different bridge bearing conditions is investigated. The obtained results show that by reducing the stiffness of the bridge bearing, the maximum values of vertical displacement and vertical acceleration of the bridge deck increase, but the vertical acceleration of the train carbody decreases.