ABSTRACT
The paper presents a review of authors work on railway ballast vibration testing on a few sites. The aim of testing is to get the level of vibration amplitude in terms of train speed and axle load. The rolling stock causes oscillations of track superstructure, which show up in the form of noise and vibration. The increase in loads and speeds of trains leads to a significant increase of dynamic vibration effects on the roadbed. Because of this exposure the intensity of uneven residual deformation accumulation of the railway track increases. It affects not only on the roadbed, but also on constructions of buildings and construction. The study of ballast vertical vibration displacement gives the following conclusions: 1. Displacement amplitudes and frequency range of ballast particles are derived. Both horizontal components increase linearly with approximately the same intensity with speed growth, and their values in the entire range of speeds do not exceed 225 µm in the transverse direction and 90 µm in the longitudinal direction. The vertical component also increases according to a nearly linear dependence up to 190 km/h, and at higher speed it stabilizes and even slightly decreases, which leads to almost the same values of the resulting vibration displacement amplitude up to 275 km/h. 2. No differences in the oscillatory process are revealed for different types of rail fastenings (KB-65, ARS-4 or Pandrol). 3. The obtained results can be used to simulate the vibrational dynamic effect in triaxial tests. Such modeling is necessary to study the sensitivity of crushed stone ballast to the loads, which is shown in a decrease in the strength and deformation properties of the ballast, to predict the bearing capacity and deformability of the ballast under various operating conditions.
