Track bed consists of structural layers and subsoil, and in the case of the ballasted track, also the structure comprises ballast bed. Together, this structure creates a layered half-space in which the load from the rail supports is distributed. The paper is focused on static analysis of track bed as a layered half-space structure.
Currently, the so-called DORNII method, developed in the Soviet Union in the mid-1950s, is still used for the assessment of the track bed structure. The evaluation of this structure is based on the assessment of the deformation resistance. The deformation resistance is assessed through the value of the deformation modulus of the sub-ballast surface and the subsoil surface. The deformation modulus is measured both in the geotechnical survey and in the acceptance process of construction works. When designing the track bed, the deformation modulus is taken into account as an essential material characteristic.
Neither the stress values relative to the depth nor deflection is analysed in the currently used methodology. The DORNII method is empirical but allows calculation of vertical stress and deflection. The authors wondered whether this method would not be too inaccurate because of increasing train speed and axle load. Two methods, analytical and finite element, were chosen for comparison. The article describes the specific analysis procedures and compares their results.

railway trackbed; elastic layered half-space; static analysis