Verification of boundary conditions of numerical modeling of the track substructure thermal regime – influence of the snow cover
Journal Title: Archives of Transport - Year 2018, Vol 4, Issue 48
Abstract
The initial part of the paper briefly characterizes a long-term experimental activity at the Department of Railway Engineering and Track Management (DRETM). The research of the DRETM focuses, besides other research activities and specific problems in the field of railway engineering (application of new structures and construction materials in conventional and modernized railway tracks, modernisation and rehabilitation of existing railway tracks for higher speeds, track diagnostics, influence of track operation on noise emissions and design of structural measures, possibility of application of recycled ballast bed material in the track substructure, ballast recycling technologies, ecological assessment of recycled material of the track substructure), on various factors affecting track substructure freezing. In 2012-2017, in the campus of the University of Žilina (UNIZA), an Experimental stand DRETM was built for the research purposes. The experimental stand DRETM consists of 6 types of track substructure placed in an embankment or a cut, in the 1:1 scale. Besides conventional building materials (crushed aggregate), these structures also include various thermal insulation materials (Liapor concrete, Styrodur, foam concrete). A significant part of the paper deals with numerical modeling of the freezing process of track substructure (an embankment with the embedded protective layer of crushed aggregate, fr. 0/31.5 mm) for various boundary conditions (air frost index, average annual air temperature), using SoilVision software. The aim of this research is to identify the thermal insulation effects of different thicknesses of snow cover on the depth of penetration of the zero isotherm into the track substructure (railway track). The paper conclusion specifies the influence of different snow cover thicknesses, or nf factor (factor expressing the dependency between the mean daily air temperature and the temperature on the ballast bed surface) and various climatic conditions (frost indexes and average annual air temperatures), affecting the railway infrastructure, on the resulting depth of freezing of the track substructure (railway track). These outputs will be in the further research used for the design of nomogram for determining the thickness of the protective layer of the frost-susceptible subgrade surface of the track substructure.<br/><br/>
Authors and Affiliations
Libor IŽVOLT, Peter DOBEŠ, Juraj PIEŠ
Keywords
Related Articles
- EP ID EP431373
- DOI 10.5604/01.3001.0012.8365
- Views 122
- Downloads 0
Control of Pump Operation by Varying Rotational Speed in the Road Infrastructure
The paper evaluates applicability of pumping plants to road infrastructure. A comparative analysis is undertaken of the cascade control system of pump operation and the control system of pump operation by varying of rota...
MODEL-BASED INVESTIGATIONS ON DYNAMIC SHIP HEELS IN RELATION TO MARITIME TRANSPORT SAFETY
The paper has been presented criteria of similarity between of liquid motion. Results of initial research on air flow’s dynamic impact on a ship model of 888 project type are presented in the elaboration as well. The res...
Parameter optimization of sea waterway system dredged to the specified depth case of the modernized Świnoujście-Szczecin fairway
The paper presents a methodology for designing and optimizing the parameters of reconstructed marine waterways dredged to a certain depth. The reconstruction comes down to a particular deepening and widening of the water...
A New Concept of Dual Fuelled SI Engines Run on Gasoline and Alcohol
The paper discusses tests results of dual-fuel spark ignition engine with multipoint injection of alcohol and gasoline, injected in area of inlet valve. Fuelling of the engine was accomplished via prototype inlet system...
MULTI-OBJECTIVE OPTIMIZATION APPLIED FOR PLANNING OF REGIONAL EUROPEAN AIRLINE
Fleet planning is very important elements in the airlines planning process. Fleet planning should answer the question which types of aircraft are required and how many of them are required taking into account the current...