Bridge Deck Analysis / Edition 2

by Eugene J. Obrien, Damien Keogh, Alan O'Connor

Overview

Captures Current Developments in Bridge Design and Maintenance

Recent research in bridge design and maintenance has focused on the serviceability problems of older bridges with aging joints. The favored solution of integral construction and design has produced bridges with fewer joints and bearings that require less maintenance and deliver increased durability. Bridge Deck Analysis, Second Edition outlines this growing development, and covers the structural analysis of most common bridge forms. It introduces reliability analysis, an emergent method that allows bridge engineers to determine risk when maintaining older or damaged bridges.

Explains the Background Theory along with Practical Tools

This book includes practical examples of everyday problems in bridge engineering, and presents real-life examples of the application of reliability analysis. The authors show how reliability analysis can determine structural safety even for bridges which have failed a deterministic assessment. They also update other chapters to reflect the most current advancements towards more sophisticated analysis, and the more widespread use of finite element software.

What’s New in this Edition:

• Incorporates new research on soil-structure interaction



• A new section with examples of how to analyze for the effects of creep



• Greatly expands the sections on 3-D brick finite elements



• Now consistent with both Eurocodes and AASHTO standards

An appropriate resource for senior undergraduates taking an advanced course on bridge engineering, Bridge Deck Analysis is also suitable for practicing engineers, and other professionals involved in the development of bridge design.

Product Details

ISBN-13:	9780367869397
Publisher:	CRC Press
Publication date:	12/10/2019
Edition description:	2nd ed.
Pages:	352
Product dimensions:	7.00(w) x 10.00(h) x (d)

About the Author

Eugene J. OBrien worked with engineering firms for five years before moving to the university sector in 1990. Since 1998 he has been professor and head of civil engineering at University College Dublin. He is the author of two books and more than 200 papers on weigh-in-motion, bridge health monitoring, and bridge loading. He has had research projects in 4th, 5th, 6th and 7th European Framework Programmes. He is co-founder and chairman of Roughan O’Donovan Innovative Solutions, a subsidiary of the engineering firm Roughan O’Donovan, designers of several landmark bridge structures.

Damien L. Keogh is a Bridge Engineer at Rambøll, Denmark

Alan J. O’Connor is an Associate Professor at Trinity College Dublin

Table of Contents

Preface xiii

Acknowledgements xv

Disclaimer xvii

Authors xix

1 Introduction 1

1.1 Introduction 1

1.2 Factors affecting structural form 1

1.3 Cross sections 2

1.3.1 Solid rectangular 2

1.3.2 Voided rectangular 3

1.3.3 T-section 4

1.3.4 Box sections 5

1.3.5 Older concepts 6

1.4 Bridge elevations 7

1.4.1 Simply supported beam/slab 8

1.4.2 Series of simply supported beams/slabs 8

1.4.3 Continuous beam/slab with full propping during construction 8

1.4.4 Partially continuous beam/slab 9

1.4.5 Continuous beam/slab: Span-by span construction 12

1.4.6 Continuous beam/slab: Balanced cantilever construction 13

1.4.7 Continuous beam/slab: Push-launch construction 16

1.4.8 Arch bridges 16

1.4.9 Frame or box culvert (integral bridge) 19

1.4.10 Beams/slabs with drop-in span 21

1.4.11 Cable-stayed bridges 22

1.4.12 Suspension bridges 24

1.5 Articulation 24

1.6 Bearings 27

1.6.1 Sliding bearings 27

1.6.2 Pot bearings 28

1.6.3 Elastomeric bearings 28

1.7 Joints 29

1.7.1 Buried joint 30

1.7.2 Asphaltic plug joint 30

1.7.3 Nosing joint 30

1.7.4 Reinforced elastomeric joint 31

1.7.5 Elastomeric in metal runners joint 31

1.7.6 Cantilever comb or tooth joint 32

1.8 Bridge aesthetics 32

1.8.1 Single-span beam/slab/frame bridges of constant depth 33

1.8.2 Multiple spans 34

2 Bridge loading 39

2.1 Introduction 39

2.2 Dead loading 40

2.3 Imposed traffic loading 41

2.3.1 Pedestrian traffic 41

2.3.2 Nature of road traffic loading 41

2.3.3 Code models for road traffic 44

2.3.4 Imposed loading due to rail traffic 45

2.4 Shrinkage and creep 46

2.4.1 Shrinkage 47

2.4.2 Creep 47

2.5 Thermal loading 47

2.5.1 Uniform changes in temperature 48

2.5.2 Differential changes in temperature 50

2.6 Impact loading 56

2.7 Dynamic effects 57

2.8 Prestress loading 61

2.8.1 Equivalent loads and linear transformation 61

2.8.2 Prestress losses 67

2.8.3 Non-prismatic bridges 69

3 Introduction to bridge analysis 73

3.1 Introduction 73

3.2 Positioning the traffic load model on the bridge 73

3.3 Differential settlement of supports 77

3.4 Thermal expansion and contraction 78

3.4.1 Equivalent loads method 81

3.5 Differential temperature effects 83

3.5.1 Temperature effects in three dimensions 93

3.6 Prestress 96

3.7 Analysis for the effects of creep 102

4 Integral bridges 109

4.1 Introduction 109

4.1.1 Integral construction 109

4.1.2 Lateral earth pressures on abutments 111

4.1.3 Stiffness of soil 114

4.2 Contraction of bridge deck 116

4.2.1 Contraction of bridge fully fixed at the supports 116

4.2.2 Contraction of bridge on flexible supports 116

4.3 Conventional spring model for deck expansion 120

4.4 Modelling expansion with an equivalent spring at deck level 123

4.4.1 Development of general expression 123

4.4.2 Expansion of frames with deep abutments 126

4.4.3 Expansion of bank-seat abutments 128

4.5 Run-on slab 131

4.6 Time-dependent effects in composite integral bridges 133

5 Slab bridge decks: Behaviour and modelling 137

5.1 Introduction 137

5.2 Thin-plate theory 137

5.2.1 Orthotropic and isotropic plates 137

5.2.2 Bending of materially orthotropic thin plates 138

5.2.3 Stress in materially orthotropic thin plates 144

5.2.4 Moments in materially orthotropic thin plates 146

5.2.5 Shear in thin plates 153

5.3 Grillage analysis of slab decks 155

5.3.1 Similitude between grillage and bridge slab 156

5.3.2 Grillage member properties: Isotropic slabs 158

5.3.3 Grillage member properties: Geometrically orthotropic slabs 162

5.3.4 Computer implementation of grillages 164

5.3.5 Sources of inaccuracy in grillage models 164

5.3.6 Shear force near point supports 166

5.3.7 Recommendations for grillage modelling 166

5.4 Planar finite element analysis of slab decks 168

5.4.1 FE theory: Beam elements 168

5.4.2 FE theory: Plate elements 171

5.4.3 Similitude between plate FE model and bridge slab 175

5.4.4 Properties of plate finite elements 176

5.4.5 Shear forces in plate FE models 178

5.4.6 Recommendations for FE analysis 179

5.5 Wood and Armer equations 182

5.5.1 Resistance to twisting moment 186

5.5.2 New bridge design 187

6 Application of planar grillage and finite element methods 189

6.1 Introduction 189

6.2 Simple isotropic slabs 189

6.3 Edge cantilevers and edge stiffening 192

6.4 Voided slab bridge decks 200

6.5 Beam-and-slab bridges 206

6.5.1 Grillage modelling 207

6.5.2 Finite element modelling 213

6.5.3 Transverse local behaviour of beam-and-slab bridges 215

6.6 Cellular bridges 215

6.6.1 Grillage modelling 216

6.7 Skew and curved bridge decks 222

6.7.1 Grillage modelling 223

6.7.2 FE modelling 224

7 Three-dimensional modelling of bridge decks 225

7.1 Introduction 225

7.2 Shear lag and effective flange width 225

7.2.1 Effective flange width 226

7.3 Three-dimensional analysis using brick elements 228

7.3.1 Interpretation of results of brick models 228

7.4 Upstand grillage modelling 239

7.5 Upstand finite element modelling 240

7.5.1 Upstand finite element modelling of voided slab bridge decks 244

7.5.2 Upstand FE modelling of other bridge types 247

7.5.3 Prestress loads in upstand FE models 248

8 Probabilistic assessment of bridge safety 251

8.1 Introduction 251

8.2 Code treatment of probability of failure 252

8.2.1 Eurocode 1990 253

8.2.2 ISO/CD 13822:2010 254

8.2.3 Nordic Committee on Building Regulations 255

8.2.4 International Federation for Structural Concrete Bulletin 65 255

8.2.5 AASHTO 256

8.3 Calculation of the probability of failure, P_f 256

8.3.1 Basic statistical concepts 258

8.4 Resistance modelling 262

8.4.1 Reinforced concrete 263

8.4.2 Prestressed concrete 265

8.4.3 Structural steel 265

8.4.4 Soils 266

8.4.5 Material model uncertainty 266

8.5 Deterioration modelling 268

8.6 Load modelling 273

8.6.1 Permanent and quasi-permanent loads 273

8.6.2 Variable imposed loads 274

8.7 Probabilistic assessment of LS violation 274

8.8 Component vs. system reliability analysis 275

9 Case studies 277

9.1 Introduction 277

9.2 Reinforced concrete beam-and-slab deck 277

9.2.1 Bridge model 277

9.2.2 Probabilistic classification and modelling 280

9.2.3 Results of probabilistic assessment 285

9.3 Post-tensioned concrete slab deck 287

9.3.1 Bridge model 288

9.3.2 Probabilistic classification and modelling 289

9.3.3 Results of probabilistic assessment 291

9.4 Steel truss bridge 293

9.4.1 Bridge model 294

9.4.2 Probabilistic classification and modelling 296

9.4.3 Results of probabilistic assessment 299

9.5 Conclusion 301

References 303

Appendix A Stiffness of structural members and associated bending moment diagrams 309

Appendix B Location of centroid of a section 311

Appendix C Derivation of shear area for grillage member representing cell with flange and web distortion 313

Index 315

Editorial Reviews

"This book is very useful for both teaching and designing purposes."
—Dr. Stergios Mitouls, University of Surrey, UK

"A book of this type risks being accused of being superficial to the expert and overly complex to the graduate. This is not the case.... A worthy successor to Hambly's Bridge Deck Behaviour."

—Richard Cooke, Proceedings of the ICE: Bridge Engineering

From the Publisher