Examining the Influence of Railway Track Routing on the Thermal Regime of the Track Substructure – Experimental Monitoring

2019 ◽  
pp. 201-209
Author(s):  
Peter Dobeš ◽  
Libor Ižvolt ◽  
Stanislav Hodás
Keyword(s):  
Thermal Regime ◽  
Railway Track ◽  
Track Substructure

scholarly journals NUMERICAL MODELLING OF THERMAL REGIME OF RAILWAY TRACK - STRUCTURE WITH THERMAL INSULATION (STYRODUR)

2021 ◽  
Vol 27 (7) ◽  
pp. 525-538
Author(s):  
Libor Ižvolt ◽  
Peter Dobeš ◽  
Michaela Holešová ◽  
Deividas Navikas
Keyword(s):  
Numerical Modelling ◽  
Thermal Insulation ◽  
Thermal Regime ◽  
Climatic Factors ◽  
Railway Track ◽  
Track Structure ◽  
Insulation Layer ◽  
Surface Level ◽  
Main Factors ◽  
Climatic Characteristics

This paper presents the results of numerical modelling of the influence of various factors (geometrical layout of the structural layers of the railway track, climatic factors and ballast fouling) on the freezing of railway track structure with a built-in thermal insulation layer of extruded polystyrene (Styrodur). At the same time, the suitability and expediency of incorporating the thermal insulation layer at the sub-ballast upper surface level (i.e. below the rail ballast construction layer), or at the level of subgrade surface are discussed. Numerical modelling results in the main factors that should be taken into account in the dimensioning of the sub-ballast layers with a built-in thermal insulation layer. Based on the data on the depth of freezing of the railway track structure obtained from numerical modelling, a design nomogram for dimensioning was created and subsequently the influence of the changes of climatic characteristics on the freezing of the railway track structure was then mathematically expressed.

Using Time Domain Reflectometry to Determine Depth of Fouling and Fouling Type in Railway Track Substructure

2018 ◽  
Vol 42 (1) ◽  
pp. 20170305
Author(s):  
Abdullah Alsabhan ◽  
Dante Fratta ◽  
Benjamin J. Warren ◽  
James M. Tinjum ◽  
Tuncer B. Edil
Keyword(s):  
Time Domain ◽  
Time Domain Reflectometry ◽  
Railway Track ◽  
Track Substructure

Case study of use of falling weight deflectometer to investigate railway infrastructure constructed upon soft subgrades

2016 ◽  
Vol 53 (12) ◽  
pp. 1991-2000 ◽  
Author(s):  
Parisa Haji Abdulrazagh ◽  
Michael T. Hendry
Keyword(s):  
Dynamic Modelling ◽  
Railway Track ◽  
Falling Weight Deflectometer ◽  
Railway Infrastructure ◽  
Time Histories ◽  
Single Mass ◽  
Least Squares Curve Fitting ◽  
Track Substructure ◽  
Falling Weight

Falling weight deflectometer (FWD) testing was conducted along with embankment and subgrade sampling over 210 km (130 miles) of Canadian National Railway’s Lac La Biche Subdivision, which runs between Edmonton and Fort McMurray, as a part of a larger investigation of the line for increased axle loads. The resulting measurements were evaluated for their ability to identify soft subgrades. Two analyses were conducted to this end. First, the statistical distribution of peak deflections recorded by the FWD was investigated for different types of subgrade material. Second, the properties of track substructure were studied by characterizing the deflection time histories using a dynamic model of a single mass on a viscoelastic foundation and least-squares curve fitting. Four characteristic types of deflection time histories were identified for differing substructure conditions. Simplified dynamic modelling of railway track substructure showed that where relatively thick embankment exists over subgrade, the response of track is overdamped behavior.

Track Substructure Design Methodology and Data

2010 ◽  
Author(s):  
Theodore R. Sussmann ◽  
James P. Hyslip
Keyword(s):  
Material Properties ◽  
High Speed ◽  
Progressive Failure ◽  
Failure Process ◽  
Structure Design ◽  
Design Methods ◽  
Railway Track ◽  
Track Structure ◽  
Design Data ◽  
Track Substructure

Track substructure design is an often overlooked step in the design of railroad track. The lack of consideration for the substructure when designing track results in greater maintenance demands due to inadequate track substructure performance. Railway track is a stable structure with a progressive failure process that allows track engineers to manage the degradation of the track through maintenance. However, increasing demands for track availability from high traffic volumes require that track maintenance be minimized while ensuring safety. Additionally, developing high speed rail and intercity passenger rail on existing corridors necessitates higher levels of substructure performance due to tighter track roughness tolerances. Reduction in maintenance needs can be achieved by ensuring that new construction and rehabilitation projects be designed to provide a stable track structure throughout the design life. Lack of readily available data for substructure materials is a drawback to the use of track design methods. This paper provides a summary of several available substructure track design methods along with the required data for design. The track design data is related to track measurements that could be used to determine much of the information necessary for design of track rehabilitation. Track load-deflection data could be used to develop much of the needed design data while ground penetrating radar could support delineation of similar track segments. Benefits of track structure design include knowledge of expected life, reduced maintenance, material properties for quality control, and development of material properties that could permit application of performance based contract specifications.

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