timber railroad bridges
TRANSCRIPT
![Page 1: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/1.jpg)
TIMBER RAILROAD BRIDGESTIMBER RAILROAD BRIDGES
Terry WipfDoug WoodBrent Phares
Iowa State University
Mike RitterForest Products Laboratory
![Page 2: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/2.jpg)
OVERVIEWOVERVIEW
Timber used in RR bridges more than 100 years (many still in service)Solid sawn lumber superstructuresRailroads need to be made aware of value of glued laminated options for rehabilitation and new constructionResearch and education needed to identify most cost effective options
![Page 3: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/3.jpg)
PERTINENT PAST/CURRENT PERTINENT PAST/CURRENT ACTIVITIESACTIVITIES
Testing and evaluation of RR bridges in TexasTesting and evaluation of RR bridge in Washington stateResearch needs study
![Page 4: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/4.jpg)
BACKGROUNDBACKGROUND--Testing and Testing and Evaluation of RR BridgesEvaluation of RR Bridges
Existing timber bridges on SP railway lineLong term performance – >60 years
Recent heavy axle loads Condition assessment Rehabilitation program to strength existing bridge (evaluation of effectiveness)
![Page 5: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/5.jpg)
OPEN DECKOPEN DECK
Packed Chord
TieOpen Deck
Bent Bent Bent Bent
Packed Chord
![Page 6: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/6.jpg)
![Page 7: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/7.jpg)
BALLAST DECKBALLAST DECK
Ballast Deck
![Page 8: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/8.jpg)
Typical Damage and DeteriorationTypical Damage and Deterioration
![Page 9: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/9.jpg)
Existing Stringer ConditionExisting Stringer Condition
Can’t see interior stringers when in place
![Page 10: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/10.jpg)
““ExperimentalExperimental”” Usage of Glued Usage of Glued Laminated StringersLaminated Stringers
![Page 11: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/11.jpg)
RESEARCH PROGRAMRESEARCH PROGRAM
D’Hanis bridge testTest trainRevenue trafficStatic and dynamic loadsDeflections, accelerations and wheel loads
![Page 12: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/12.jpg)
Civil and Construction Engineering
DD’’HANIS BRIDGEHANIS BRIDGE
approx. 165'-8"
Span 8
Span 2
Bent 2test spans
helper bent
![Page 13: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/13.jpg)
DD’’HANIS BRIDGEHANIS BRIDGE
Cross Section - Span 8
4 stringer chord(glued laminated)
4 stringer chord(sawn)
![Page 14: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/14.jpg)
DD’’HANIS BRIDGEHANIS BRIDGE
Cross Section - Span 2
4 stringer chord(glued laminated)
helper stringer
5 stringer chord (sawn)
![Page 15: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/15.jpg)
![Page 16: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/16.jpg)
Glued laminated packed chord
Solid sawn chord with helper
![Page 17: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/17.jpg)
INSTRUMENTATIONINSTRUMENTATION
STRINGER 8
STRINGER 1
SPAN 8BENT 9 BENT 8
displacement transducer
accelerometer
![Page 18: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/18.jpg)
Measuring Shear DeformationsMeasuring Shear Deformations
![Page 19: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/19.jpg)
Instrumented Rails for Load Instrumented Rails for Load EstimationEstimation
![Page 20: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/20.jpg)
![Page 21: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/21.jpg)
Controlled Test TrainControlled Test Train
![Page 22: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/22.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSTest Train Wheel LoadsTest Train Wheel Loads
16 18 20 22 24 26
0
10.0
20.0
30.0
40.0
50.0 DRGW25101
SPMW4337
SPMW4345
EMD6870
Whe
el lo
ad (k
ip)
Time ( sec.)
![Page 23: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/23.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSDynamic Load FactorDynamic Load Factor
Velocity(mph)
MaximumWheel Load
in Span 8(kips)
MaximumWheelLoad
in Span 2(kips)
MaximumWheel Load
on Approach (kips)
Span 8DLF
Span 2DLF
ApproachDLF
crawl
15
30
40
41.0
41.6
41.6
41.0
40.0
40.7
46.8
40.7
40.0
39.8
42.8
53.1
-
1.02
1.01
1.00
-
1.02
1.17
1.02
-
1.00
1.06
1.32
![Page 24: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/24.jpg)
LOAD TEST RESULTSLOAD TEST RESULTS
60 80 100 120 140-0.250
-0.200
-0.150
-0.100
-0.050
0.000
0.050
Def
lect
ion
(in)
Time (sec)8 9 10 11 12 13
-0.250
-0.200
-0.150
-0.100
-0.050
0.000
0.050
Def
lect
ion
(in)
Time (sec)
Slow Fast
![Page 25: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/25.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSDynamic Amplification FactorDynamic Amplification Factor
Test TrainVelocity(mph)
15
30
40
Test TrainVelocity
DAF
Span 2 Span 8
NorthChord
SouthChord
NorthChord
SouthChord
1.00 1.05 1.00 1.00
1.15 1.05 1.07 1.01
1.22 1.06 1.14 1.07
Span 2 Span 8
NorthChord
SouthChord
NorthChord
SouthChord
1.00 1.05 1.00 1.00
1.15 1.05 1.07 1.01
1.22 1.06 1.14 1.07
![Page 26: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/26.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSSpan 8Span 8
7 8 9 10 11 12-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
Def
lect
ion
(in)
Time (sec.)7 8 9 10 11 12
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
Def
lect
ion
(in)
Time (sec.)
Sawn Chord Glulam Chord
![Page 27: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/27.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSSpan 2 vs. Span 8Span 2 vs. Span 8
7 8 9 10 11 12-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
Def
lect
ion
(in)
Time (sec.)8 9 10 11 12 13
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
STRINGER HDef
lect
ion
(in)
Time (sec)
Sawn ChordSpan 8
Sawn ChordSpan 2
![Page 28: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/28.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSSpan 2Span 2
8 9 10 11 12 13-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
STRINGER H
Def
lect
ion
(in)
Time (sec)8 9 10 11 12 13
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
Def
lect
ion
(in)
Time (sec)
Sawn Chord Glulam Chord
![Page 29: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/29.jpg)
LOAD TEST RESULTSLOAD TEST RESULTSSpan 8 Span 8 -- GlulamGlulam
0 10 20 30 40 50 60 70 80-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1D
efle
ctio
n (in
)
Time (sec)
ExperimentalAnalytical - ContinuousAnalytical - Simple
![Page 30: TIMBER RAILROAD BRIDGES](https://reader031.vdocument.in/reader031/viewer/2022011722/586a4bd91a28abd31d8b9d54/html5/thumbnails/30.jpg)
Research Needs StudyResearch Needs Study
Currently in progressSeeking to define what research is needed to advance the use of timber by railroads