Railway Substructure
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Transcript of Railway Substructure
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 1
UW – Madison Geological and
Geotechnical Engineering
Geological Engineering Transporta1on Geotechnics Civil & Environmental Engineering
University of Wisconsin-Madison
Andrew Keene, Jim Tinjum, Tuncer Edil, and Randy Brown
Railway Substructure Stabilization with Polyurethane Injections
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 2
Outline Background
• Problem • Motivation
Materials • Rigid-Polyurethane Foam (RPF) • Polyurethane-Stabilized Ballast (PSB)
Methods for Mechanical Property Evaluation • Plastic deformational behavior • Compressive and flexural properties
Feasibility of Strategically Placed Polyurethane Layer in Track-Substructure • Evaluate track mechanical behavior after stabilization
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 3
Background: Railway Track Components
Deterioration in the substructure leads to permanent deformation in the track, threatening rail operations
Prevent track deformation while enhancing rail operations
Ballast layer deteriorates under numerous loading repetitions Problem:
Objective:
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 4
Motivation: Track Maintenance Costs Maintenance of ballast is $500M/ year
• For 150,000 km of Class 1 freight rail in the US, (Chrismer and Davis 2000)
Fouling Level Increases During Service Life of Track
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 5
Types of Fouling
(Ebrahimi et al. 2010)
Coal Fouling Mineral Fouling Clay Fouling
Non-‐Cohesive Fouling (i.e., between P4 & P200) Cohesive Fouling (i.e., P200)
P4 = 4.75 mm; P200 = 0.075 mm
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 6
UW-Madison Railroad Research Mitigating Ballast Fouling Impact and Enhancing Rail
Freight Capacity • Prevent ballast layer deterioration and track deformation • Enhance railway track capacity and maintained capabilities • Polyurethane reinforcement of ballast layer is proposed
Steve Reed
Dr. Randy Brown Andrew Keene
Ben Warren
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 7
Materials: Uretek USA Inc. Polyurethane
Uretek Polyurethane: Rigid-Polyurethane Foam High density, expanding, thermoset, resin system
Reaches 90% of full compressive and tensile strength in 15 minutes
Research Involves Use of Technology With Rail Ballast
Rigid-Polyurethane Foam (RPF) Polyurethane-Stabilized Ballast (PSB)
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 8
Methods: Large-Scale Cyclic Triaxial (LSCT)
300-mm
600-mm
Cyclic loading machine to simulate railway traffic
Automated data acquisition system (LabView)
Axle load: 20, 30, and 40 tons
Equivalent to: Deviator Stress, σ = 300 kPa Confining Stress, σ = 90 kPa
(Ebrahimi 2011)
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 9
Flexural Beam Testing
L = 0.4 m
Unconfined Compressive Strength Testing
L = 0.76 m
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 10
0
0.5
1
1.5
2
2.5
3
3.5
300 350 375 400
Cum
ulat
ive
Plas
tic S
trai
n, ε
P (%
)
Deviator Stress, σd (kPa)
Fouled Ballast, FI 5% & MC 15%
Clean Ballast
PS-Clean Ballast
PS-Fouled Ballast, FI 25% & MC 15%
PS-Recycled Ballast, P25.4 mm & R19 mm
Results: Stabilized and Un-stabilized
MC = % Moisture Content FI = Fouling Index (%)= P4+P200
Clean Ballast Reference Line
PS = Polyurethane Stabilized P4 = 4.75 mm P200 = 0.075 mm
Tested over 200,000 loading repetitions in cyclic triaxial compression
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 11
PSB and Constituent Mechanical Properties
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
Com
pres
sive
Flex
ural
Tens
ile
Com
pres
sive
Flex
ural
Tens
ile
Com
pres
sive
Flex
ural
Tens
ile
PSB RPF Ballast
Mec
hani
cal S
tren
gths
(kPa
)
0
50
100
150
200
250
300
350
400
450
500
Com
pres
sive
Flex
ural
Tens
ile
Com
pres
sive
Flex
ural
Tens
ile
Com
pres
sive
Flex
ural
Tens
ile
PSB RPF Ballast
Elas
tic M
odul
i (M
Pa)
ρRPF = 200 kg/m3
ρb = 1,580 kg/m3
RPF = Rigid Polyurethane Foam
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 12
Material Property Summary
Mechanical Properties • PSB plastic deformational behavior far less than clean
ballast, recycled ballast, and fouled ballast • PSB elastic moduli typically less than ballast
Further Considerations and Restated Questions: • Effect of lower modulus on overall track response? • Fatigue lifecycle for PSB layers?
Next Step: Modeling PSB in Track-Substructure
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 13
PSB Model – Percolation-Injection
RPF = Rigid Polyurethane Foam
Concept: Model percolation-injection method for PSB stabilization
Goal: Determine track elastic response
Result: Areas of lower modulus did not have negative impact
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 14
3D–View
Longitudinal View
Lateral View PSB Trackbed Layer
PSB Model – Subsurface-Injection
Concept: Model subsurface-injection method for PSB trackbeds
Goal: Determine strain at base of layer for input into analytical fatigue model
Result: Strain measured would give PSB fatigue lifecycle at 500-1000 MGT
RPF = Rigid Polyurethane Foam εt = Flexural Strain
(Rose & Konduri 2006)
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 15
Conclusions
Mechanical Properties
• PSB outperforms other track-substructure materials
• PSB had typically higher elastic deformational behavior
Feasibility of Stabilization in Track-Substructure
• Stabilization does not have negative impact on elastic response
• Injection methods are feasible for track stabilization
• PSB can greatly increase track mechanistic lifecycle
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 16
Future Work Ballast Stabilization with Polyurethane:
• Evaluation of polyurethane-stabilized ballast with varying levels of fouling and water content
• Use of method in field-scale tests or track maintenance operations
Warning System and Inspection Project: • Correlate fouling conditions found using GPR and TDR with track
deformation measure with FOS
• Select track segment for case study evaluation of inspection methods
University of Wisconsin-Madison Rail Research: • Incorporate results from Mechanistic and non-destructive evaluation
research into test track or field application
• Continue to advance geotechnical approaches for enhancing track inspection techniques, maintenance prediction, and sustainability using mechanistic-based research
• Evaluate impacts of frac sand loads on new and existing Wisconsin rail infrastructure
Mid-‐Con(nent Research Forum 2012 September 6 Keene, Edil, Tinjum, & Brown University of Wisconsin-‐Madison Slide 17
Questions?
Acknowledgements
Center for Freight Infrastructure Research and Education (CFIRE)
Uretek USA Inc.
UW-Madison Laboratory Staff: • William Lang
• Xiaodong ‘Buff’ Wang
Special Thanks To: • Dr. Ali Ebrahimi
• Zhipeng Su
References
ASTM Standards, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA
Ebrahimi, A. (2011). “Deformational Behavior of Fouled Railway Ballast.” PhD thesis, Department of Civil and Environmental Engineering, University of Wisconsin, Madison.
Ebrahimi, A. and Keene, A.K. Maintenance Planning of Railway Ballast, In proceedings of the AREMA 2011 Annual Conference, Minneapolis, Minnesota, September 18-22.
Keene, A. (2012). “Mitigating ballast fouling and enhancing rail-freight capacity.” MS thesis, Dept. of Civil and Env. Eng., University of Wisconsin-–Madison.
Rose, J.G. & Konduri, K.G. (2006). "KENTRACK–A Railway Trackbed Structural Design Program." AREMA 2006 Annual Conference, Louisville, Kentucky, September 17-20. • Gizem Bozkurt
• Ben Warren