The Influence of the Track Axis Curvature at Railway Filler-Beam Deck Bridges

The article presents a comparative study between the simplified method calculation proposed by the prescriptions of design codes and the analysis with the FEM program LUSAS [1], regarding the influence of the curvature of the track axis at railway bridges with steel beams embedded in concrete.

The study was made on three simply supported bridges with the openings chosen so as to cover the openings used for this constructive solution, namely 10m ≤L≤30m. For each analysed opening the curve radius of the track axis was varied, in the domain in which are representative as effects, namely 100m ≤R≤1500m. In the case of Lusas FEM analysis, a physically nonlinear analysis it was previously carried out, after which the cracked concrete was removed, as its participation in the structural stiffness is practically non-existent.

Studying the outcomes revealed by the two calculations presented, it can be concluded that the simplified method proposed by the design codes leads to a overvaluation of the track axis curvature influence at the railway filler-beam deck bridges.