Adoption of the response spectra method for calculating the dynamic response of railway bridges

This paper introduces a simplified method for calculating the dynamic response of railway bridges under train service loads. Response spectrum analysis, which has proved itself in structural dynamics, has been adopted for the given problem. If essential parameters such as the natural frequency, mass, span and damping of a bridge are known, the maximum response quantities can be looked up in a diagram. Preparation of the response spectra diagrams is computationally intensive but they do provide an easy and quick way of obtaining accurate results. This method is exemplified for single-span bridges and the load models defined in the Eurocode. However, it is possible to expand the theory to more complex bridge systems and other load models without difficulty. With the aid of this method, the maximum dynamic response of a bridge under moving loads can be calculated in an efficient and convenient way with the accuracy required by the current design codes.