scholarly journals Investigation into Some Design Aspects of Ballasted Railway Track Foundations using Numerical Modelling

2018 ◽  
Author(s):  
Md. Abu Sayeed ◽  
Mohamed A. Shahin
Keyword(s):  
Numerical Modelling ◽  
Railway Track

scholarly journals Modelling of Railway Track Temperature Regime with Real Heat-Technical Values for Different Climatic Characteristics

2017 ◽  
Vol 13 (2) ◽  
pp. 134-142 ◽  
Author(s):  
Stanislav Hodás ◽  
Alžbeta Pultznerová
Keyword(s):  
Numerical Modelling ◽  
Temperature Regime ◽  
Railway Track ◽  
High Quality ◽  
Time Operation ◽  
Negative Temperatures ◽  
Freezing Period ◽  
Long Time ◽  
Climatic Characteristics

Abstract High quality of railway track construction is a major priority. One of the quality elements is the resistance to load of railway formation with individual structural layers caused by negative temperatures during the critical freezing period of winter. Numerical modelling allows obtaining more control outputs at different climatic loads. The presented paper shows the load of railway track model with different variants of climate and shows the importance in the designing of the non-transport load under negative temperatures, i.e. observation of transition of the zero isotherm through the layers of railway subgrade. If the subgrade layers of the railway formation are built with high quality and durability then the axis of the track will keep its geometric spatial position during the long-time operation.

scholarly journals Design of ballasted railway track foundations using numerical modelling. Part II: Applications

2018 ◽  
Vol 55 (3) ◽  
pp. 369-396 ◽  
Author(s):  
Md. Abu Sayeed ◽  
Mohamed A. Shahin
Keyword(s):  
Numerical Modelling ◽  
Case Studies ◽  
Design Method ◽  
Field Measurements ◽  
Railway Track ◽  
Moving Loads ◽  
Practical Application ◽  
Field Case ◽  
Repeated Applications ◽  
Good Agreement

This paper is the second of two companion papers in relation to a new design method for ballasted railway track foundations. Development of the new design method has been explained in the first paper (i.e., Part I: Development), and the procedures for using the method and its practical application on some field case studies are presented in this paper. A special feature of the proposed design method is that it considers the true impact of train dynamic moving loads and number of repeated applications of the traffic tonnage. The proposed method is applied to four case studies of actual tracks and the results are compared with field measurements and found to be in good agreement. It should be noted that, although the proposed design method is able to overcome most shortcomings of the existing methods and found to provide excellent outcomes, further verification with more field case studies is highly desirable.

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.

Three-dimensional numerical modelling of railway track with varying air voids content bituminous subballast

2020 ◽  
pp. 1-19
Author(s):  
Talita de Freitas Alves ◽  
Paulo André Moraes Pereira ◽  
Rosângela Motta ◽  
Kamilla Vasconcelos ◽  
Jamilla Lutif Teixeira ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Three Dimensional ◽  
Railway Track ◽  
Air Voids

scholarly journals Transverse Cracking of Concrete Base Plate in CRTS III Ballastless Track Structure: Effects of Environmental Boundary Conditions

2021 ◽  
Vol 11 (21) ◽  
pp. 10400
Author(s):  
Weiqiang Guo ◽  
Xin Huang ◽  
Lijun Zhao ◽  
Ya Wei
Keyword(s):  
Numerical Modelling ◽  
Boundary Conditions ◽  
Base Plate ◽  
Test Series ◽  
Railway Track ◽  
Early Age ◽  
Track Structure ◽  
Transverse Cracking ◽  
Ballastless Track ◽  
Concrete Base

The cast-in-place concrete base plate is a main member of the China Railway Track System (CRTS) III ballastless track structure that is prone to generating early transverse cracking. Such cracks can dramatically affect the performance and service life of the railway track structure. This study investigated the influence of temperature and moisture boundary conditions on early cracking behavior of the CRTS III base plate by using approaches of both in situ measurements and numerical modelling. In-site measurements of strain and temperature were made in four test series of CRTS III base plates under the same natural environmental condition but cured with different regimes, and a total of 96 measuring positions were monitored for up to 150 days. The results showed that the strain magnitude and distribution in the field base plate, the initial time at cracking, and the observed cracking pattern varied significantly between the different test series. In order to understand the mechanisms that create these transverse cracks and to provide guidelines for the current curing strategy during construction, the characteristics of temperature-induced and moisture-induced stresses were analyzed by using 3D numerical modelling and by considering early-age concrete creep properties, meteorological factors, and the influence from environmental boundary conditions. The calculated results revealed that early-age transverse cracking in CRTS III base plate depends more on drying shrinkage stress than temperature stress. By conducting this study, we expect to provide guidance for reducing or eliminating early cracks of CRTS III concrete base plate.

The Use of Array Processors for Numerical Modelling of Tidal Estuary Dynamics

1980 ◽  
Author(s):  
D. Prandle ◽  
E.R. Funke ◽  
N.L. Crookshank ◽  
R. Renner
Keyword(s):  
Numerical Modelling ◽  
Tidal Estuary ◽  
Array Processors
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