jerry g. pe professor civil engineeringjrose/papers/ts 2008 worskshop... · 2008. 3. 21. ·...
TRANSCRIPT
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Dr. Jerry G. Rose, PEProfessor of Civil Engineering
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6a
Periodic Replacement of Track ComponentsPeriodic Replacement of Track Components
6b
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10a
10b
10c
10d
PlatesStrain gauge
Pressure Cell
Junction Box
Battery
Zero Deflection Reference Rod
LVDT
LVDTPin
Cell Placement on Asphalt
Cell Location at Richmond
2 1
4 3
0
5
10
15
20
25
30
9 10 11 12 13 14 15 16 17 18 19 20 21 22
Initial 2 Cars2 6‐Axle Locomotives
0
5
10
15
20
25
30
9 10 11 12 13 14 15 16 17 18 19 20 21 22
2 6‐Axle Locomotives Initial 2 Cars
0
5
10
15
20
25
30
9 10 11 12 13 14 15 16 17 18 19 20 21 22
2 6‐Axle Locomotives Initial 2 Cars
0
5
10
15
20
25
30
9 10 11 12 13 14 15 16 17 18 19 20 21 22
2 6‐Axle Locomotives Initial 2 Cars
Loaded Coal Train at Richmond
P‐Cell 822 C/L Track and Tie
P‐Cell 820 Beneath Rail and Tie
P‐Cell 821 C/L Track in Crib
P‐Cell 819 Beneath Rail in Crib
Time (s) Time (s)
Time (s) Time (s)
Pressure (p
si)
Pressure (p
si)
Pressure (p
si)
Pressure
(psi)
0
5
10
15
20
25
30
2 3 4 5 6 7 8 9 10
0
5
10
15
20
25
30
2 3 4 5 6 7 8 9 10
0
5
10
15
20
25
30
2 3 4 5 6 7 8 9 10
0
5
10
15
20
25
30
2 3 4 5 6 7 8 9 10
Initial 2 Cars
Initial 2 CarsInitial 2 Cars
Initial 2 Cars1 6‐Axle Loco
1 4‐Axle Loco
1 6‐Axle Loco
1 4‐Axle Loco
1 6‐Axle Loco
1 4‐Axle Loco
1 6‐Axle Loco
1 4‐Axle Loco
Loaded Auto Train at Richmond
P‐Cell 822 C/L Track and Tie
P‐Cell 820 Beneath Rail and Tie
P‐Cell 821 C/L Track in Crib
P‐Cell 819 Beneath Rail in Crib
Time (s) Time (s)
Time (s) Time (s)
Pressure (p
si)
Pressure (p
si)
Pressure (p
si)
Pressure
(psi)
2 6‐Axle Locos Initial 6 Cars
2 6‐Axle Locos Initial 6 Cars
2 6‐Axle Locos Initial 6 Cars
05
1015202530
2 3 4 5 6 7 8 9 10
Time (s)
Stre
ss (p
si) 8 in. HMA surface
Subgrade surface
Reduction of Dynamic Stresses
ThicknessBallast/HMA
in.
Vertical CompressiveStress on Ballast
KPV/ITD, psi
Vertical CompressiveStress on HMAKPV/ITD, psi
Vertical CompressiveStress on Subgrade
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 / –
ThicknessBallast/HMA
in.
Vertical CompressiveStress on Ballast
KPV/ITD, psi
Vertical CompressiveStress on HMAKPV/ITD, psi
Vertical CompressiveStress on Subgrade
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
Daniel Durrett
William Long
Bei Su
Lindsay Walker
Frank Tuehues
Karthik Konduri
CSX Transportaion&
TTCI (Pueblo)