Guidelines for the Load and Resistance Factor Design and Rating of Riveted and Bolted Gusset-Plate Connections for Steel Bridges (2013)

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ii Modeling Philosophy ............................................................................................................ 54  Geometric Imperfections .................................................................................................. 55  Material Properties ............................................................................................................ 56  Fastener Strengths ............................................................................................................. 56  Failure Criteria .................................................................................................................. 57  Analysis Matrix ..................................................................................................................... 60  Plate Thickness ................................................................................................................. 61  Mill-to-Bear versus Non-Mill-to-Bear Compression Splices ........................................... 61  Material Strength .............................................................................................................. 61  Member Chamfer versus No Member Chamfer ............................................................... 61  Shingle Plates .................................................................................................................... 62  Edge Stiffening ................................................................................................................. 62  Corrosion........................................................................................................................... 62  CHAPTER 3. FINDINGS AND APPLICATIONS.................................................................. 66  EXPERIMENTAL SPECIMENS ............................................................................................. 66  ANALYTICAL ......................................................................................................................... 70  SYNTHESIS OF RESULTS ..................................................................................................... 70  Shear Failures ....................................................................................................................... 70  Buckling Failures .................................................................................................................. 74  Free Edge Slenderness ...................................................................................................... 77  Chord Splice .......................................................................................................................... 94  Tension Members .................................................................................................................. 97  Block Shear ....................................................................................................................... 97  Whitmore Yield and Fracture ........................................................................................... 98  Coupling of Tension Modes with Other Limit-States ....................................................... 98  Other Tensile Failure Modes ............................................................................................ 98  Multi-Layered Plates .......................................................................................................... 100  Edge Stiffening .................................................................................................................... 103  Corrosion ............................................................................................................................ 106  Rivet Shear Strength ........................................................................................................... 112  Strength Data .................................................................................................................. 112  Connection Length Reduction ........................................................................................ 115  SUMMARY OF PROFESSIONAL FACTOR STATISTICS ................................................ 118  CHAPTER 4. RESISTANCE FACTOR CALIBRATION ................................................... 120  CALIBRATION METHOD ................................................................................................... 120  Assumed Calibration Statistics ........................................................................................... 121  System Factors .................................................................................................................... 123  Dead-to-Live Load Ratios for Trusses ................................................................................ 123  EXISTING FHWA GUIDE LEVEL OF RELIABILITY ....................................................... 125  Buckling Failure ................................................................................................................. 125  Shear Failure ...................................................................................................................... 126 

iii Block Shear ......................................................................................................................... 127  Recommended Target Reliability Index .............................................................................. 127  SAMPLE -FACTOR EXPLANATION ................................................................................ 128  SHEAR CALIBRATION ....................................................................................................... 129  Shear Rupture ..................................................................................................................... 130  BUCKLING CALIBRATION ................................................................................................ 130  TENSION CALIBRATION ................................................................................................... 133  CHORD SPLICES .................................................................................................................. 134  RIVET SHEAR CALIBRATION ........................................................................................... 136  ANALYSIS FACTOR CALIBRATION ................................................................................ 138  SUMMARY OF RESISTANCE FACTORS .......................................................................... 139  Reliability at Manual for Bridge Evaluation (MBE) Operating Level ............................... 139  -Factor for Shear Yielding Limit-State ............................................................................ 140  Rivets ................................................................................................................................... 140  CHAPTER 5. CONCLUSIONS AND RECOMMENDATIONS ......................................... 146  SUGGESTED RESEARCH ................................................................................................... 151  REFERENCES .......................................................................................................................... 152  APPENDIX A – REVIEW OF BRIDGE PLANS APPENDIX B – LOAD FRAME APPENDIX C - FASTENER CHARACTERIZATION APPENDIX D – MATERIAL TEST RESULTS APPENDIX E – PHOTOSTRESS DATA APPENDIX F – DIC DATA APPENDIX G – STRAIN GAUGE DATA APPENDIX H – FARO DATA APPENDIX I – GEORGIA TECH PARAMETRIC STUDY FINAL REPORT APPENDIX J – PROPOSED CHANGES TO AASHTO SPECIFICATIONS APPENDIX K – DESIGN EXAMPLES BASED ON DRAFT SPECIFICATION

1 ACKNOWLEDGMENTS The research reported in this report was performed under direction of the Federal Highway Administration in collaboration with the National Cooperative Highway Research Program for NCHRP Project 12-84, “Guidelines for the Load and Resistance Factor Design and Rating of Riveted and Bolted Gusset-Plate Connections for Steel Bridges.” The author of this report would to thank the following for their contributions in conducting this research; it could not have been a success without their diligent efforts. First and foremost, I’d like to thank Dr. William Wright and Dr. Joseph Hartmann who were the first and second principle investigators on this project; they set the path of the project and I merely completed it. The following Turner-Fairbank Highway Research Center staff from the Structures Laboratory were integral in conducting the experimental testing: Fassil Beshah, Linfeng Chen, Kevin Deasy, Gary Greene, Paul Ryberg, Brian Story, Tim Tuggle, Robert Zobel, and interns Zachary May and Colby Nurse. Collaboration in developing the experimental program and the laborious task of conducting all the finite element simulations was completed by the Georgia Institute of Technology under the direction of Professors Roberto Leon and Donald White, Dr. Yoon Duk Kim, Yavuz Mentes, Mohammad Towhid Bhuiyan, and Jong Wan Hu. Final thanks should be given to those who helped with internal Federal Highway Administration (FHWA) reviews of the work, namely Thomas Everett, Dr. Joseph Hartmann, Dr. Firas Ibrahim, Dr. Brian Kozy, and Lou Triandafilou.