The mechanical responses of railway tracks through shear forces

Owing to increases in axle load, operational density, authorized speed and train size, continuous evaluations of railway track, which consider dynamic loads, have become increasingly crucial to ensure the efficiency and safety of railways. In this article, a theoretical and experimental analysis of the mechanical behaviour of a railway track was developed. A numerical model was formulated treating the rail as a continuous elastically supported beam, following the Winkler foundation concept. By applying concentrated vertical loads and varying the stiffness of the supports, the shear forces on the beam were determined for different scenarios. Experimentally, a strain gauge was installed on the rail of a Brazilian railway, and shear strain data were collected from multiple passes of loaded wagons at different speeds and directions. A numerical procedure was proposed to standardize the experimental data and compare them with the results previously deduced from a simplified superstructure model. The theoretical and experimental results largely agreed, and the dimensionless parameters obtained from the experimental results were related to those obtained by the numerical model, finally estimating the value of the track modulus.