INFLUENCE OF PIER NONLINEARITY, IMPACT ANGLE, AND COLUMN SHAPE ON PIER RESPONSE TO BARGE IMPACT LOADING By BIBO ZHANG A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ENGINEERING UNIVERSITY OF FLORIDA 2004 ACKNOWLEDGEMENTS I would like to thank my research advisor, Dr. Gary Consolazio for providing continuous guidance, excellent research ideas, detailed teaching and all this with a lot of patience. I am thankful for being able to learn so much during the past year and a half. I would also like to extend my gratitude to Florida Department of Transportation for providing funding for this project. I would like to express my heartfelt thanks to all the graduate students who worked on this project, especially Ben Lehr, David Cowan, Alex Biggs and Jessica Hendrix. Their research helped me enormously in completing my thesis. My family and friends have been very supportive throughout this effort. I wish to thank them for their understanding and support. ii TABLE OF CONTENTS page ACKNOWLEDGEMENTS................................................................................................ ii LIST OF TABLES...............................................................................................................v LIST OF FIGURES ........................................................................................................... vi ABSTRACT....................................................................................................................... ix CHAPTER 1 INTRODUCTION ........................................................................................................1 1.1 Overview.................................................................................................................1 1.2 Background of AASHTO Guide Specification ......................................................2 1.3 Objective.................................................................................................................4 2 AASHTO BARGE AND BRIDGE COLLISION SPECIFICATION .........................5 3 FINITE ELEMENT BARGE IMPACT SIMULATION .............................................9 3.1 Introduction.............................................................................................................9 3.2 Background Study ................................................................................................10 3.3 Pier Model Description.........................................................................................14 3.4 Barge Finite Element Model.................................................................................19 3.5 Contact Surface Modeling ....................................................................................26 4 NON-LINEAR PIER BEHAVIOR DURING BARGE IMPACT .............................31 4.1 Case Study ............................................................................................................31 4.2 Analysis Results....................................................................................................32 5 SIMULATION OF OBLIQUE IMPACT CONDITIONS .........................................37 5.1 Effect of Strike Angle on Barge Static Load-Deformation Relationship.............38 5.2 Effect of Strike Angle on Dynamic Loads and Pier Response.............................40 5.3 Dynamic Simulation Results ................................................................................42 iii 6 EFFECT OF CONTACT SURFACE GEOMETRY ON PIER BEHAVIOR DURING IMPACT.....................................................................................................52 6.1 Case Study ............................................................................................................52 6.2 Results...................................................................................................................52 7 COMPARISON OF AASHTO PROVISIONS AND SIMULATION RESULTS ....63 8 CONCLUSIONS ........................................................................................................67 LIST OF REFERENCES...................................................................................................69 BIOGRAPHICAL SKETCH .............................................................................................71 iv LIST OF TABLES Table page 3-1 Comparison of original and adjusted section properties ..........................................16 3-2 Input data in LS-DYNA simulations........................................................................18 3-3 Comparison of plastic moment and displacement using properties of pier cap.......19 3-4 Comparison of plastic moment and displacement using properties of pier column......................................................................................................................19 3-5 General modeling features of the testing barge........................................................25 4-1 Dynamic simulation cases........................................................................................32 5-1 Dynamic simulation cases........................................................................................41 7-1 Peak forces computed using finite element impact simulation ................................66 v LIST OF FIGURES Figure page 1-1 Relation between impact force and barge damage depth according to Meir- Dornberg’s Research (after AASHTO [1]) ................................................................3 2-1 Collision energy to be absorbed in relation with collision angle and the coefficient of friction (after AASHTO [1])................................................................8 3-1 Global modeling of San-Diego Coronado Bay Bridge (after Dameron [10])..........11 3-2 Pier model used for local modeling (after Dameron [10]) .......................................12 3-3 Global pier modeling for seismic retrofit analysis (after Dameron [10]).................12 3-4 Mechanical model for discrete element (after Hoit [11]).........................................13 3-5 Bilinear expression of moment-curvature and stress-strain curve ...........................17 3-6 Moment-curvature derivation...................................................................................18 3-7 Main deck plan of the construction barge ................................................................20 3-8 Outboard profile of the construction barge ..............................................................20 3-9 Typical longitudinal truss of the construction barge................................................20 3-10 Typical transverse frame (cross bracing section) of the construction barge ............20 3-11 Dimension and detail of barge bow of the construction barge.................................21 3-12 Layout of barge divisions.........................................................................................22 3-13 Meshing of internal structure of zone-1 ...................................................................23 3-14 Buoyancy spring distribution along the barge..........................................................26 3-15 Pier and contact surface layout.................................................................................27 3-16 Rigid links between pier column and contact surface..............................................27 3-17 Exaggerated deformation of pier column and contact surface during impact..........28 vi 3-18 Comparison of impact force versus crush depth for rigid and concrete contact models ......................................................................................................................29 3-19 Overview of barge and pier model for dynamic simulation.....................................30 4-1 Comparison of impact force history for severe impact case ....................................34 4-2 Comparison of impact force history for non-severe case.........................................34 4-3 Impact force and crush depth relationship comparison for severe impact case .......35 4-4 Comparison of impact force – crush depth relationship for non-severe case ..........35 4-5 Comparison of pier displacement for severe impact case ........................................36 4-6 Comparison of pier displacement for non-severe case.............................................36 5-1 Static crush between pier and open hopper barge ....................................................38 5-2 Results for static crush analysis conducting with a 4 ft. wide pier ..........................39 5-3 Results for static crush analysis conducting with a 6 ft. wide pier ..........................39 5-4 Results for static crush analysis conducting with a 8 ft. wide pier ..........................40 5-5 Layout of barge head-on impact and oblique impact with pier................................41 5-6 Impact force in X direction for high speed impact on rectangular pier ...................44 5-7 Impact force in X direction for high speed impact on circular pier. ........................44 5-8 Impact force in X direction for low speed impact on rectangular pier.....................45 5-9 Impact force in X direction for low speed impact on circular pier ..........................45 5-10 Impact force in Y direction for high-speed oblique impact .....................................46 5-11 Impact force in Y direction for low speed oblique impact.......................................46 5-12 Force-deformation results for high speed