Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure...
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Transcript of Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure...
![Page 1: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/1.jpg)
Kentrack
• Kentrack is a computer program designed to analyze a railroad track segment as a structure
• Uses Bousinessq’s Elastic Theory• Uses Burmister’s
Multi-Layer System and Finite Element Analysis to perform calculations
![Page 2: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/2.jpg)
Introduction
• Critical Stresses and Strains are Calculated• Design Lives are Predicted• Based on Fatigue Effects (Cumulative Damage
Criteria) of Repeated Loadings• Uses DAMA Program – Developed for Highway
Pavements
![Page 3: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/3.jpg)
Background
• Originally Kentrack was written in FORTRAN for DOS operation
• Since been upgraded to a Windows Platform• 3.0 was written in Visual Studio using a .Net
Framework in C#
![Page 4: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/4.jpg)
Background
• The original development goal was to analyze traditional All-Granular trackbeds and Asphalt Underlayment trackbeds
• 3.0 has the option for• All-Granular• Asphalt Underlayment• Combination – Granular & Asphalt
![Page 5: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/5.jpg)
All-Granular• Traditional Track structure
![Page 6: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/6.jpg)
Asphalt• Underlayment
![Page 7: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/7.jpg)
Combination• Contains an asphalt layer and a granular
subballast layer
![Page 8: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/8.jpg)
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Kentrack Theory• Superposition of Loads
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![Page 9: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/9.jpg)
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Kentrack Theory• Finite Element Method– Used to calculate the stress and strain in the rail
and tie
![Page 10: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/10.jpg)
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Kentrack Theory• Multilayered System– Used to calculate the stress and strain in each layer
![Page 11: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/11.jpg)
Kentrack Theory• Each type of trackbed is composed of different
materials– All-Granular trackbed layers include Ballast,
Subballast, and Subgrade– Asphalt trackbed layers include Ballast, Asphalt
and Subgrade– Combination trackbed layers include Ballast,
Asphalt, Subballast, and Subgrade• Different equations are used to describe the
properties of each material
![Page 12: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/12.jpg)
Kentrack Theory
• Ballast– In new trackbeds the ballast behaves non-linearly– In aged trackbeds the ballast behaves linearly
• Subgrade – Behaves as a linear elastic material
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![Page 13: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/13.jpg)
Kentrack Theory• Asphalt is a visco-elastic material• The dynamic modulus depends on the
following:– Temperature– Aggregate passing the No. 200 sieve in %– Volume of bitumen %– Volume of air voids %– Asphalt viscosity– Load frequency
![Page 14: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/14.jpg)
Kentrack Theory
• Damage Analysis– Based on minor linear damage analysis criteria– Performance is based on periods• For Kentrack this is four seasons
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Kentrack Theory
• Predicted number of repetitions
•Each car equals one repetition
![Page 16: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/16.jpg)
Kentrack Theory• Predicted number of repetitions
Wheel Load = 36000 lb/wheel
For one car the total weight = 36000 lb/wheel x 8 = 286,000 lb/rep / 2000
= 143 ton/rep
The number of repetitions assumed per year = 200,000 rep/yr
The traffic per year = 200,000 rep/yr x 143 ton/rep
= 28,600,000 GT/yr / 1 x 106
= 28.6 MGT/yr
![Page 17: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/17.jpg)
Subgrade Damage Analysis• Excessive permanent deformation controls
failure• Deformation is governed by the vertical
compressive stress on the top of the subgrade• Based on Highway experience• The number of allowable repetitions before
failure
583.3734.3510837.4 scd EN
![Page 18: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/18.jpg)
Asphalt Damage Analysis• Fatigue cracking controls failure• Fatigue cracking is governed by the tensile
strain in the bottom of the asphalt• Based on highway experience• The number of allowable repetitions before
failure
853.0291.30795.0 ata EN
![Page 19: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/19.jpg)
Failure Criteria• All-Granular Trackbed • Vertical Compressive Stress on Subgrade
![Page 20: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/20.jpg)
Failure Criteria• Asphalt Trackbed• Vertical Compressive Stress on Subgrade,
Tensile Strain at Bottom of Asphalt
![Page 21: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/21.jpg)
Kentrack Theory• Combination Trackbed• Vertical Compressive Stress on Subgrade,
Tensile Strain at Bottom of Asphalt
![Page 22: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/22.jpg)
Typical cross section• All-Granular Trackbed
Sub. Mod. = 15,000 psi28.6 MGT/yr
![Page 23: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/23.jpg)
Typical cross section• Asphalt Trackbed
Sub. Mod. = 15,000 psi28.6 MGT/yr
![Page 24: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/24.jpg)
Typical cross section• Combination Trackbed
Sub. Mod. = 15,000 psi28.6 MGT/yr
![Page 25: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/25.jpg)
Critical Outputs*
Variable All-GranularTrackbed
AsphaltTrackbed
CombinationTrackbed
Subgrade Vertical Compressive Stress (psi) 14.47 11.69 10.49
Asphalt Strain (in/in) N/A 0.000134 0.000116
Service life of Subgrade (yrs) 10.27 25.56 38.38
Service life of Asphalt (yrs) N/A 24.89 39.80
*Axle Load = 36 tons, Sub. Mod. = 15,000 psi, 28.6 MGT/yr
![Page 26: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/26.jpg)
Material Properties
• Properties to be inputted are often industry standards or specified by the railroad
• Several properties are set as defaults as noted in the tutorial
• The majority of default values can be changed by the user
![Page 27: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/27.jpg)
Effect of Subgrade Modulus on Subgrade Compressive Stress
![Page 28: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/28.jpg)
Effect of Subgrade Modulus on Subgrade Design Life
36 Ton Axle Load28.6 MGT/yr
6000 12000 18000 210000
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Subgrade life in All Granular-Trackbed
Subgrade life in Asphalt Trackbed
Subgrade life in Combination Trackbed
Subgrade Modulus (psi)
Subg
rade
Des
ign
Life
(yea
rs)
![Page 29: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/29.jpg)
Effect of Subgrade Modulus on Asphalt Tensile Strain
![Page 30: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/30.jpg)
6000 12000 18000 210000
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Asphalt Life in Asphalt Trackbed
Asphalt Life in Combination Trackbed
Subgrade Modulus (psi)
Asph
alt D
esig
n Lif
e (y
ears
)Effect of Subgrade Modulus on Asphalt Design Life
36 Ton Axle Load28.6 MGT/yr
![Page 31: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/31.jpg)
Kentrack• The output values are stored automatically in
a text file that is over written in each new analysis
• The text file can be saved by the user after the analysis
• Through the input process the program validates inputs
• Results can be used for performance-based structural design and analysis
![Page 32: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/32.jpg)
Summary• Kentrack is a versatile program for the design and
analysis of All-Granular, Asphalt Underlayment, and Combination Trackbeds
• Subgrade compressive stress, asphalt tensile strain, and associated design lives are computed
• Design lives are considered conservative since they are based on highway failure criteria
• The relative effects of varying input parameters can be assessed
![Page 33: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/33.jpg)
Asphalt Trackbed Tutorial • Start the program• Select the
trackbed to be analyzed
![Page 34: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/34.jpg)
![Page 35: Kentrack Kentrack is a computer program designed to analyze a railroad track segment as a structure Uses Bousinessq’s Elastic Theory Uses Burmister’s Multi-Layer.](https://reader035.fdocuments.in/reader035/viewer/2022062712/56649c9d5503460f9495c7c6/html5/thumbnails/35.jpg)
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