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University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnCivil Engineering Theses, Dissertations, andStudent Research Civil Engineering
4-2017
Optimizing Steel Railway Truss Bridge HealthMonitoringAhmed RagehUniversity of Nebraska-Lincoln, [email protected]
Daniel LinzellUniversity of Nebraska-Lincoln, [email protected]
Follow this and additional works at: http://digitalcommons.unl.edu/civilengdiss
Part of the Civil Engineering Commons, Construction Engineering and Management Commons,Structural Engineering Commons, and the Transportation Engineering Commons
This Article is brought to you for free and open access by the Civil Engineering at DigitalCommons@University of Nebraska - Lincoln. It has beenaccepted for inclusion in Civil Engineering Theses, Dissertations, and Student Research by an authorized administrator ofDigitalCommons@University of Nebraska - Lincoln.
Rageh, Ahmed and Linzell, Daniel, "Optimizing Steel Railway Truss Bridge Health Monitoring" (2017). Civil Engineering Theses,Dissertations, and Student Research. 104.http://digitalcommons.unl.edu/civilengdiss/104
Ahmed Rageh (MS), Daniel Linzell (Ph.D., P.E., F. ASCE) – University of Nebraska-Lincoln
Model Calibration
• Model:ü3D frame model PLUSüRails/tiesüGeometric offsets, connections
Bridge Under Study
• Multi-Span Steel Through-TrussüDouble-TracküRiveted ConstructionüEyebars
• Condition Foci:üStringer-to-floor beam connectionsüStringer and truss bottom lateralsüEyebarsüBearings
Objectives
Problems – Condition Evaluation
• Visual inspection:üPrescribed frequencyüCostlyüSubjected to human interpretation
• Sensors:üFocused on a single bridgeüExtensive arrayüCostly
Analysis Based Health Monitoring Plan
Problems - Steel Railway Trusses
• Aging• Large system – bridge AND railway• Labor intensive condition eval• Reported conditions:üStringer-to-floor beam connections
[Haghani 2012]üStringer flange clip angle cracks
[Haghani 2012]üUnequal eyebars stress
distribution [DelGrego 2008]üDisplaced eyebar pins [DelGrego 2008]
Conclusions, Future Work• Validated model - published test results• Field tests/model calibration – SHM
planning• Proposed SHM plans• Validated SHM plans - field monitoring
• Sensitivity Analyses:üModified models - mimic reported
condition - 20 modelsüE.G. – cracked connection
Stringer-to-floor beamconnection
Stringer flange clipAngle
Hea
lth m
onito
ring
syst
em
Initial steps
Initial field testing instrumentation planning
Initial field testing, model calibration
Final steps
Analysis based health monitoring plans
Verify analysis based health monitoring plans via testing
30’-6
”
Samples
• Initial field testing plan:
Initial Field Testing
Truss
Flooring system
Bracing system
Rails
Ties
Bot. lat. -11.25”
Str. 18.75”
FB18.75”
Truss bot.0.00”
Str. lat.24.00”
5.70
4.793.943.82
5.345.22
-4.0
0.0
4.0
8.0
6 7 8 9 10
Stre
ss (k
si)
Time (Sec)
Stringer mid-span bottom stresses
Field Results (B4519) Field Results (B4520)Model Results (B4519) Model Results (B4520)
1.16
Assumed conditions
• Proposed health monitoring plan:ü~2200 permutations ü3 proposed plans
-1.5
0.0
1.5
3.0
8 9 10 11 12 13
Stre
ss (k
si)
Time (Sec)
Stringer #1 end-span bottom stressesField Results (B4539) Model Results (B4539) Defected
Stress reduced