Mechanism Methodology for Structural Health Monitoring of Arch Bridges BY CHAD FISCHER BS ...

213 Pages·2011·5.1 MB·English

Mechanism Methodology for Structural Health Monitoring of Arch Bridges

BY

CHAD FISCHER
B.S., University of Illinois at Urbana‐Champaign, 1999
M.S., University of Illinois at Urbana‐Champaign, 2000

THESIS

Submitted as partial fulfillment of the requirements
for the degree of Doctor of Philosophy in Civil Engineering
in the Graduate College of the
University of Illinois at Chicago, 2011

Chicago, Illinois

Defense Committee:
Dr. Farhad Ansari, Chair and Advisor
Dr. Michael McNallan
Dr. Eduard Karpov
Dr. Didem Ozevin
Dr. Aftab Mufti, University of Manitoba, Winnipeg, Manitoba, Canada
This thesis is dedicated to my wife, Lisa, and son, Jake, who provided never ending
encouragement of my research. They made numerous sacrifices to allow me the time to
complete this work as I spent many hours at the library and in the laboratory. Their
motivation and never ending love made this possible.

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ACKNOWLEDGEMENTS

I would like to acknowledge Dr. Farhad Ansari for without him, this study and research
would not have been possible. His passion for structural health monitoring research
was contagious and made this study exciting and successful. Dr. Ansari is a leader in the
industry of structural health monitoring. His insights and ideas for monitoring plans
and analysis provided a great foundation for developing new ideas.

My thesis committee and fellow researchers provided many hours of their time
reviewing my work and helping refining my research focus. Dr. Aftab Mufti, Dr. Michael
McNallan, Dr. Eduard Karpov, Dr. Didem Ozevin, and Dr. Ernesto Indocochea all took
time from their busy schedules to review my thesis work and encourage future
development. Fellow researcher, Iman Talebinejad, was an invaluable resource and
friend during all of our field monitoring and laboratory testing. Asad Bassam, Amir
Iranmanish, and Ali Zarafshan also spent countless hours listening to ideas and assisting
with laboratory test setups.

Also, I would like to recognize the New York City Department of Transportation and in
particular, the work of Dr. Bojidar Yanev and Kevin McAnulty. Dr. Sreenivas Alampalli of
the State of New York Department of Transportation was also instrumental in making
this study a success. Dr. Yanev and Dr. Allampalli have a great vision toward bridge
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management and maintenance. They have an eye toward the future of bridge
maintenance and inspection.

Finally, I would also like to acknowledge Engineering Systems Inc. for their support and
freedom in allowing me to complete this work. Dr. August Domel and Dr. Daniel
Wojnowski were instrumental in assisting with the resources needed for my PhD work.

CRF

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TABLE OF CONTENTS

CHAPTER PAGE

1. INTRODUCTION.........................................................................................................................................1
1.1. Motivation for Research...............................................................................................................3
1.2. Structural Health Monitoring....................................................................................................9
1.3. History of Masonry Arch Design and Construction.......................................................12
1.4. Statement of Need and Importance.....................................................................................13
1.5. Thesis Statement..........................................................................................................................17

2. BACKGROUND AND LITERATURE REVIEW...............................................................................19
2.1. Structural Life of a Masonry Arch.........................................................................................19
2.1.1. Hingeless Arch......................................................................................................................19
2.1.2. Two Hinge Arch....................................................................................................................20
2.1.3. Three Hinge Arch................................................................................................................21
2.2. Masonry Arch Analysis ‐ Pre 1900......................................................................................25
2.2.1. Rule of Thumb Design equations..................................................................................25
2.2.2. Navier 1826...........................................................................................................................26
2.2.3. Castigliano 1879..................................................................................................................26
2.2.4. Brooklyn Bridge...................................................................................................................29
2.3. Masonry Arch Analysis ‐ Post 1900.....................................................................................30
2.3.1. Pippard Elastic Analysis...................................................................................................30
2.3.2. MEXE (Military Engineering Experimental Establishment) Method............35
2.3.3. Heyman....................................................................................................................................38
2.3.4. Limit State Analysis............................................................................................................42
2.3.5. Rigid Block Analysis...........................................................................................................46
2.3.6. Finite Element Modeling..................................................................................................49
2.4. Comparison of Masonry Arch Bridge Analysis Methods............................................52

3. FIELD TESTING: SHM OF BROOKLYN BRIDGE APPROACH STRUCTURE.....................55
3.1. Visual Inspection and Study of Existing Bridge Documentation.............................55
3.2. SHM System....................................................................................................................................59
3.2.1. Sensor Instrumentation...................................................................................................64
3.2.2. Sensor Layout Plan.............................................................................................................69
3.3. Long Term Monitoring Over Remote Data Network....................................................75
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4. LABORATORY TESTING: SUPPORT MOVEMENT TESTS OF SCALED LABORATORY
MODELS OF BROOKLYN BRIDGE ARCH...........................................................................................82
4.1. Arch Design and Test Setup.....................................................................................................82
4.2. Material Properties.....................................................................................................................84
4.3. Test Summary and Results......................................................................................................88
4.3.1. Arch Test A.............................................................................................................................88
4.3.2. Arch Test B.............................................................................................................................94
4.3.3. Test C.....................................................................................................................................101
4.3.4. Test D.....................................................................................................................................106

5. CURRENT STUDY AND PROPOSED FORMULATION............................................................110
5.1. Methodology Background and Development................................................................121
5.1.1. Applying the Methodology...........................................................................................132
5.1.2. Estimating Crack Opening Displacement...............................................................135
5.1.3. Thrust Line Visualization..............................................................................................135
5.1.4. Nonlinear Buckling Analysis for Failure Load.....................................................136
5.1.5. Study on the Number of Gap Elements...................................................................146
5.2. Methodology Verification.......................................................................................................150
5.2.1. Comparison with Laboratory Tests..........................................................................150
5.2.2. Comparison with Ultimate Load Analysis Methods..........................................160
5.2.3. Comparison with Full Scale Load Test....................................................................172
5.2.4. Summary of Load Comparisons.................................................................................175
5.2.5. Comparison with Pippard Studies............................................................................176
5.3. Applying the Methodology ‐ Case Study with Brooklyn Bridge SHM Data.......180
5.3.1. Tilt of Supporting Walls.................................................................................................180

6. CONCLUSIONS.......................................................................................................................................188

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LIST OF TABLES

TABLE PAGE

Table 1. Summary of Department of Transport Analysis Method Comparison..................53
Table 2. Test summary, refer to Figure 42 for defined support movement direction.....84
Table 3. Average material properties for test arch...........................................................................87
Table 4. Arch dimensions used in analysis models.......................................................................122
Table 5. Horizontal vs. vertical displacement ratios for all outward support movement
tests...................................................................................................................................................153
Table 6. Comparison of laboratory test data and proposed methodology analysis........159
Table 7. Comparison of Ultimate Load Calculations.....................................................................176

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LIST OF FIGURES

FIGURE PAGE

Figure 1. Satellite view of lower Manhattan and Brooklyn. Brooklyn Bridge main span in
red and Manhattan approach spans in yellow...................................................................7
Figure 2. Brooklyn Bridge looking south, area of investigation highlighted...........................7
Figure 3. Brooklyn Bridge looking north, area of investigation highlighted...........................8
Figure 4. South elevation of Brooklyn Bridge masonry arch approach spans.........................8
Figure 5. Hingeless arch with thrust line shown within the limits of the middle third
cross section..................................................................................................................................20
Figure 6. Two hinged arch with hinges at supports.........................................................................21
Figure 7. Three‐hinged arch with support movement...................................................................23
Figure 8. Nomenclature for three hinge arch analysis....................................................................24
Figure 9. Free body diagram for three hinge arch analysis...........................................................25
Figure 10. Castigliano arch diagram.......................................................................................................28
Figure 11. Bridge considered by Pippard, where h = fill thickness at crown and d = arch
barrel thickness at crown.....................................................................................................32
Figure 12. Nomenclature for Pippard analysis..................................................................................33
Figure 13. Nomenclature for Heyman method..................................................................................41
Figure 14. Plane of N rigid arch blocks at described by Livesley for limit analysis...........44
Figure 15. Free body diagram of element 3 from Figure 14........................................................44
Figure 16. Block j and contact forces for interface i for rigid block formulation.................47
Figure 17. UK Department of Transport Analysis Method comparison.................................53
Figure 18. Diagram of arches and crack locations...........................................................................57
Figure 19. Longitudinal crack at the crown of the arch.................................................................58
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Figure 20. Vertical masonry cracks indicating past differential settlement.........................58
Figure 21. Inspection opening in arch showing 2’ brick thickness and granite rubble fill.
..........................................................................................................................................................59
Figure 22. Detail of armored cable used on Brooklyn Bridge.....................................................60
Figure 23. Core alignment fusion splicer.............................................................................................61
Figure 24. Mechanical fiber optic connector......................................................................................61
Figure 25. Micron Optics’ sm130 interrogator unit........................................................................63
Figure 26. Interrogator and data collection system at the Brooklyn Bridge........................63
Figure 27. Cellular antenna installation...............................................................................................64
Figure 28. Fiber optic crack gauge and accelerometer..................................................................67
Figure 29. Fiber optic tiltmeter................................................................................................................69
Figure 30. Section view of arch approach structure with sensor layout................................70
Figure 31. Sensor layout at arch intrados.............................................................................................71
Figure 32. Sensor layout at third floor...................................................................................................72
Figure 33. Sensor layout at second floor...............................................................................................73
Figure 34. Sensor layout at first floor.....................................................................................................74
Figure 35. Sensor layout at basement....................................................................................................75
Figure 36. Screenshot of remote bridge monitoring software...................................................77
Figure 37. Typical example of daily FBG crack sensor reading...................................................78
Figure 38. Crack sensor reading from west arch..............................................................................78
Figure 39. Crack sensor reading from east arch...............................................................................79
Figure 40. Temperature sensor readings.............................................................................................81
Figure 41. Tiltmeter sensor readings.....................................................................................................81
Figure 42. Test setup configuration of laboratory arch tests......................................................83
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Figure 43. Dimensions of laboratory test arches..............................................................................83
Figure 44. Masonry compression tests.................................................................................................86
Figure 45. Summary of sample masonry prism tests.....................................................................86
Figure 46. Modulus of rupture test setup............................................................................................87
Figure 47. Arch test setup...........................................................................................................................89
Figure 48. Fiber optic sensor layout.......................................................................................................89
Figure 49. Crack at crown being measured by fiber optic crack sensors..............................90
Figure 50. Hinge formation just off center of crown.......................................................................90
Figure 51. Typical hinge formation at support..................................................................................91
Figure 52. Horizontal thrust vs. horizontal displacement plots for Test A...........................92
Figure 53. Arch stiffness from Test A.1 and Test A.2 (plot zoomed into range of 0.0
inches to 0.60 inches)............................................................................................................93
Figure 54. Relationship between support movement and vertical displacement at crown.
..........................................................................................................................................................94
Figure 55. Initial hinge formation at crown........................................................................................95
Figure 56. Fully cracked hinge at crown (located 2 courses from center)............................96
Figure 57. Hinge formation at supports...............................................................................................96
Figure 58. Thrust vs. displacement plot, Arch Test B.....................................................................98
Figure 59. Stiffness values for Test B load displacement plot....................................................98
Figure 60. Horizontal displacement vs. vertical deflection for Test B.....................................99
Figure 61. FBG crack gauge data for test B.3. ..................................................................................101
Figure 62. Crack at quarter point, Arch Test C................................................................................102
Figure 63. Crack condition after repetitive test cycles.................................................................103
Figure 64. Thrust vs. displacement plot for Test Arch C.............................................................104
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