Live-Load Testing and Finite-Element Analysis of a Steel Cantilever Deck Arched Pratt Truss

181 Pages·2017·13.86 MB·English

Utah State University
LIVE-LOAD TESTING AND FINITE-ELEMENT ANALYSIS OF A STEEL
CANTILEVERED DECK ARCHED PRATT TRUSS BRIDGE FOR
THE LONG-TERM BRIDGE PERFORMANCE PROGRAM
by
Matthew P. Laurendeau
A thesis submitted in partial fulfillment
of the requirements for the degree
of
MASTER OF SCIENCE
in
Civil and Environmental Engineering
Approved:
__________________________________ ____________________________________
Paul J. Barr Marvin W. Halling
Major Professor Committee Member
__________________________________ __________________________________
Joseph A. Caliendo Byron R. Burnham
Committee Member Dean of Graduate Studies

UTAH STATE UNIVERSITY
Logan, Utah
2011
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Copyright © Matthew P. Laurendeau 2011
All Rights Reserved
iii

ABSTRACT
Live-Load Testing and Finite-Element Analysis of a Steel Cantilevered Deck Arched
Pratt Truss Bridge for the Long-Term Bridge Performance Program
by
Matthew P. Laurendeau, Master of Science
Utah State University, 2011
Major Professor: Dr. Paul J. Barr
Department: Civil and Environmental Engineering
The Long Term Bridge Performance (LTBP) program is an organization
within the Federal Highway Administration that inspects, tests, analyzes, and
observes, for an extended period of time, a variety of bridge types throughout the
United States. Part of the program includes periodic testing of select bridges of a
span of 20 years. The Kettle River Bridge located outside of Sandstone, Minnesota
was selected for study due to its unique design.
The Kettle River Bridge is a historical steel cantilevered deck arched Pratt
truss bridge. The bridge was instrumented with 151 strain gauges on various floor
and truss members along with eight displacement gauges strategically placed along
the truss. All gauges were read simultaneously as the bridge underwent non-
destructive live loading. The recorded gauge readings were analyzed to determine
bridge behavior and then used in the assistance of calibrating a working finite-
element model.
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After a working model was verified the distribution factors for the interior
and exterior floor stringers were determined. By using the controlling distribution
factor, a load rating for the bridge was determined for both inventory and operating.
The distribution factors and load ratings determined using the working finite-
element model were then compared to the AAHSTO LRFD specifications.
(180 pages)
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ACKNOWLEDGMENTS
I would like to thank all those who have helped make this research possible.
First, I would like to thank my wife, Amanda, for always being there and supporting
me in every way she knew how and continues to unconditionally give that support.
I would also like to thank my family who have always believed in me and
encouraged me to always do my best. Also, to my fellow colleagues, I would like to
say thank you for being a great help by expounding on certain key principles.
I would also like to thank the help of Bridge Diagnostics Inc. (BDI) for their
help in the instrumentation, collection, and correlation of measured gauge readings
for the Kettle River Bridge. Thank you to Kayde Roberts for providing some of the
quality photographs used in this thesis.
Finally, I would like to make a special thanks to Dr. Paul Barr who oversaw
the research of this thesis. The kindness, enthusiasm, support, encouragement, and
relentless assistance he provided never went unnoticed and shall never be
forgotten.
Matthew Laurendeau
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CONTENTS
Page

ABSTRACT ................................................................................................................................................ iii

ACKNOWLEDGMENTS .......................................................................................................................... v

LIST OF TABLES ..................................................................................................................................... ix

LIST OF FIGURES .................................................................................................................................... x

CHAPTER

1. INTRODUCTION ..................................................................................................................... 1

Introduction .......................................................................................................................... 1
Organization .......................................................................................................................... 5

2. LITERATURE REVIEW ......................................................................................................... 7

Introduction .......................................................................................................................... 7

Hao (2010) .................................................................................................................... 8
Trautner (1989) ........................................................................................................... 9
Boothby and Craig (1997) ..................................................................................... 11
Mabsout et al. (1997) .............................................................................................. 12
Bowen (2003)............................................................................................................. 13
Yost et al. (2005) ....................................................................................................... 15

3. LIVE-LOAD TESTING ......................................................................................................... 17

Bridge Description ........................................................................................................... 17
Instrumentation Plan...................................................................................................... 28
Live-load Testing .............................................................................................................. 35
Strain Results ..................................................................................................................... 39

Floor stringer strains ............................................................................................... 40
Truss member strains ............................................................................................. 47

Displacement Results ..................................................................................................... 52
High Speed Dynamic Results ....................................................................................... 54

4. FINITE-ELEMENT MODEL .............................................................................................. 60
vii

Finite-Element Model Description ............................................................................ 60
Strain Comparisons ......................................................................................................... 72

Floor stringer strain comparisons ..................................................................... 72
Truss member strain comparisons .................................................................... 78

Displacement Comparisons ......................................................................................... 82
Load Distribution Factor ............................................................................................... 88

AASHTO live load distribution factors .............................................................. 89
Finite-element model distribution factors ...................................................... 93

Load Rating ......................................................................................................................... 97

5. SUMMARY AND CONCLUSIONS .................................................................................. 101

Summary ........................................................................................................................... 101
Conclusions....................................................................................................................... 102

REFERENCES ....................................................................................................................................... 104

APPENDICES ........................................................................................................................................ 105

Appendix A: Member Sizes ................................................................................................ 106
Appendix B: Instrumentation Plans ............................................................................... 109
Appendix C: As-Built Model Comparisons ................................................................... 120
Appendix D: Floor System Strain .................................................................................... 124

Floor Stringer Cross Section Comparisons .......................................................... 125
Floor Stringer Influence Line Comparisons ......................................................... 128
Floor Beam Strain Influence Line ............................................................................ 138
Floor Stringer Correlations ........................................................................................ 139

Appendix E: Truss Member Strain .................................................................................. 140

Truss Member Strain Influence Lines .................................................................... 141
Truss Member Strain Correlations .......................................................................... 148
Truss Member Bending Strains ................................................................................ 149

Appendix F: Displacements ............................................................................................... 152

Displacement Influence Lines ................................................................................... 153
Displacement Correlations ......................................................................................... 161
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Appendix G: High Speed Dynamic Results................................................................... 162
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LIST OF TABLES
Table Page
1 AASHTO Distribution Factors ................................................................................................. 93
2 AASHTO and FEM Distribution Factor Comparison ....................................................... 97
3 AAHSTO LFD, LRFR, and FEM Load Rating Comparison ............................................ 100