1 Dr. Jerry G. Rose, PE Professor of Civil Engineering 2 3 4 5 - PowerPoint PPT Presentation

1 Dr. Jerry G. Rose, PE Professor of Civil Engineering

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6a Periodic Replacement of Track Components Periodic Replacement of Track Components

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Plates Strain gauge

Junction Box Pressure Cell Battery

LVDT Zero Deflection LVDT Reference Rod Pin

Cell Placement on Asphalt

Cell Location at Richmond 4 3 2 1

Loaded Coal Train at Richmond P ‐ Cell 819 Beneath Rail in Crib P ‐ Cell 820 Beneath Rail and Tie 30 30 2 6 ‐ Axle Locomotives Initial 2 Cars 25 25 Pressure (psi) Pressure (psi) 20 20 2 6 ‐ Axle Locomotives Initial 2 Cars 15 15 10 10 5 5 0 0 9 10 11 12 13 14 15 16 17 18 19 20 21 22 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Time (s) Time (s) P ‐ Cell 821 C/L Track in Crib P ‐ Cell 822 C/L Track and Tie 30 30 25 25 Pressure (psi) 20 20 Pressure 15 15 (psi) 2 6 ‐ Axle Locomotives Initial 2 Cars 2 6 ‐ Axle Locomotives Initial 2 Cars 10 10 5 5 0 0 9 10 11 12 13 14 15 16 17 18 19 20 21 22 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Time (s) Time (s)

Loaded Auto Train at Richmond P ‐ Cell 819 Beneath Rail in Crib P ‐ Cell 820 Beneath Rail and Tie 30 30 1 6 ‐ Axle 1 4 ‐ Axle 1 6 ‐ Axle 1 4 ‐ Axle 25 25 Initial 2 Cars Loco Loco Loco Loco Initial 2 Cars Pressure (psi) Pressure (psi) 20 20 15 15 10 10 5 5 0 0 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 Time (s) Time (s) P ‐ Cell 821 C/L Track in Crib P ‐ Cell 822 C/L Track and Tie 30 30 25 25 1 6 ‐ Axle 1 4 ‐ Axle 1 6 ‐ Axle 1 4 ‐ Axle Loco Loco Loco Loco Initial 2 Cars Pressure (psi) Initial 2 Cars 20 20 Pressure 15 15 (psi) 10 10 5 5 0 0 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 Time (s) Time (s)

2 6 ‐ Axle Locos Initial 6 Cars 2 6 ‐ Axle Locos Initial 6 Cars

2 6 ‐ Axle Locos Initial 6 Cars

Reduction of Dynamic Stresses 30 8 in. HMA surface Stress (psi) 25 Subgrade surface 20 15 10 5 0 2 3 4 5 6 7 8 9 10 Time (s)

Thickness Vertical Compressive Vertical Compressive Vertical Compressive Ballast/HMA Stress on Ballast Stress on HMA Stress on Subgrade in. KPV/ITD, psi KPV/ITD, psi KPV/ITD, psi 10.0 / 5.0 47.9 / – 21.0 / 16.0 13.6 / – 10.0 / 8.0 48.7 / – 22.0 / 15.0 11.7 / – Thickness Vertical Compressive Vertical Compressive Vertical Compressive Ballast/HMA Stress on Ballast Stress on HMA Stress on Subgrade in. KPV/ITD, psi KPV/ITD, psi KPV/ITD, psi 12.0 / 4.0 43.5 / – 11.7 / 14.9 8.3 / 8.0 8.0 / 8.0 47.0 / – 21.9 / 14.9 8.2 / 7.7

• Peak Dynamic Pressures (286,000 lb cars) ≈ 20 psi max on top of HMA mat ≈ 10 psi max under HMA mat • Dynamic Track Deflections (286,000 lb cars) ≈ 0.25 inch wood tie track ≈ 0.05 inch concrete tie track

• Dynamic Track Modulus (286,000 lb cars) ≈ 2,900 lb/in/in wood tie track ≈ 7,200 lb/in/in concrete tie track • In ‐ Track Pressure Measurements Consistent • CSX Heavy Haul / TTCI High Tonnage Loop

• Moisture Contents of Subgrade / Subballast ‐ Consistent with time ‐ Remain near optimum • Waterproofing and Confinement • HMA Mat – minimum variation in temperatures • Modulus – remains near uniform • Fatigue Life ‐ ?

• Direct Pressure Measurements in Track Structure Compare Favorably with Predicted Pressures form KENTRACK

Bennett McElroy Bei Su Daniel Durrett Lindsay Walker William Long Frank Tuehues Karthik Konduri CSX Transportaion & TTCI (Pueblo)