| Autor: |
Izvolt L; Department of Railway Engineering and Track Management, University of Žilina, Univerzitná 8215/1, 010 26 Zilina, Slovakia., Dobes P; Department of Railway Engineering and Track Management, University of Žilina, Univerzitná 8215/1, 010 26 Zilina, Slovakia., Drusa M; Department of Geotechnics, University of Žilina, Univerzitná 8215/1, 010 26 Zilina, Slovakia., Kadela M; Building Research Institute (ITB), Filtrowa 1, 00-611 Warsaw, Poland., Holesova M; Department of Structural Mechanics and Applied Mathematics, University of Žilina, Univerzitná 8215/1, 010 26 Zilina, Slovakia. |
| Abstrakt: |
The article aims to present the modified structural composition of the sub-ballast layers of the railway substructure, in which a part of the natural materials for the establishment of sub-ballast or protective layers of crushed aggregate is replaced by thermal insulation and reinforcing material (layer of composite foamed concrete and extruded polystyrene board). In this purpose, the experimental field test was constructed and the bearing capacity of the modified sub-ballast layers' structure and temperature parameters were analyzed. A significant increase in the original static modulus of deformation on the surface of composite foamed concrete was obtained (3.5 times and 18 times for weaker and strengthen subsoil, respectively). Based on real temperature measurement, it was determined the high consistency of the results of numerical analyses and experimental test (0.002 m for the maximum freezing depth of the railway line layers and maximum ±0.5 °C for temperature in the railway track substructure-subsoil system). Based on results of numerical analyses, modified railway substructure with built-in thermal insulating extruded materials (foamed concrete and extruded polystyrene) were considered. A nomogram for the implementation of the design of thicknesses of individual structural layers of a modified railway sub-ballast layers dependent on climate load, and a mathematical model suitable for the design of thicknesses of structural sub-ballast layers of railway line were created. |
