No abstract

<p>The dynamic response of structures is an important aspect to consider, especially at resonance. Particularly, bridges traversed by trains are at risk, due to the repeated loading with regular interval from the axle and bogie spacings. If the risk of resonance is not accounted for in the design, the vertical acceleration of the bridge deck may exceed the allowed limits of comfort and safety. Hence, alternative, sustainable measures for reducing the vibrations in bridges are required to solve these challenges. This paper presents studies of fluid viscous dampers used to control the dynamic behaviour of high-speed railway bridges. A finite element model is used to investigate the response of an existing bridge, both prior to and after the installation of dampers, and the influence of some parameters on the efficiency of the dampers are analysed. The results from this paper show that the vertical deck acceleration is sufficiently reduced using the proposed solution.</p>

Abstract. Several of the bridges belonging to the Bothnia Line, located in northern Sweden, do not theoretically fulfil the current design limit for the vertical deck acceleration, when being subjected to high-speed trains. Hence, it is important to find appropriate vibration mitigation strategies that are applicable to railway bridges, in order to reduce the acceleration caused by passing trains. One way of solving this problem is to install external viscous dampers.A finite element solution for damper retrofit of high-speed railway bridges is proposed in this paper. The bridge is modelled as a two-dimensional Euler-Bernoulli beam, with inclined dashpots connected between the superstructure and the abutments. Furthermore, this paper highlights the influence of several parameters on the effectiveness of the dampers.1672