A methodology for the preliminary assessment of existing railway bridges for high-speed traffic

• Dynamic analyses of bridges on an existing railway network.
• The analysis is based upon a probabilistic approach.
• The dynamical model is based on analytical equations.
• A simplified approach to analyse slab-frame bridges is proposed.
• The result revealed that a large number of bridges needs more refined studies.

The Swedish government is considering upgrading the train speed along three railway lines in the Southern part of Sweden from 200 km/h to 250 km/h. According to the current design code, this requires that the bridges be examined with dynamic simulations to avoid excessive vibrations. This paper employs a method that can be used at an early stage to estimate the expected cost of upgrading a bridge network. The results revealed that 70% of the plate/beam bridges, 64% of the closed slab-frame bridges, and 41% of the open slab-frame bridges are expected to not fulfill the requirement on the maximum bridge deck acceleration for ballasted tracks.