Steel-concrete Composite Bridges Designing with Eurocodes

Transcription

1 Steel-concrete Composite Bridges Designing with Eurocodes Second edition David Coilings Independent consultant, Technical Director RB International

2 Contents pefa ton h Preface to the second edition Acknowledgements Notation xi xiii xv 00 Introduction 1 Eurocodes 0 and 1 1 Eurocodes 2, 3 and 4 3 Eurocodes 5 to 9 7 References 8 01 General concepts Introduction Structural forms Materials Composite action Shear connectors Example 1.1: Connector test 30 References Simple beam bridges Introduction Initial sizing Loads Example 2.1: A simple plate girder Initial design of girder Bracing of steelwork Initial design of the concrete slab Initial shear connector design Safety through design Environmental issues 48 References Integral bridges , Introduction 51 Soil-structure interaction 51 Example 3.1: A semi-integral bridge 54 Weathering steel 57 Compact class 1 and 2 sections 61 Portal frame structures 62 Example 3.2: Composite portal frame 63 Effects of skew 64 Example 3.3: Very high skew bridge 66 Painting 68 Shrinkage 69 Differential temperature 70 References Continuous bridges Introduction Motorway widening Moment-shear interaction 75 vii

3 4.4. Example 4.1: A continuous bridge Moment rounding Cracking of concrete Bearing stiffeners Precamber Natural frequency Loads on railway bridges Through-girder bridges Joint stiffness Example 4.2: A through-girder bridge Shear lag Fatigue 99 References Viaducts Introduction Concept design Example 5.1: A viaduct structure Articulation Construction methods Deck slab 112 References Haunches and double composite action Introduction Haunches Longitudinal shear at changes of section Hybrid girders Double-composite action Example 6.1: A haunched girder Slender webs Web breathing Lightweight concrete 126 References Box girders Introduction Behaviour of boxes Diaphragms Example 7.1: Railway box Efficient box girders Example 7.2: Types of composite box Noise from bridges Shear connectors for composite boxes Composite plates Example 7.3: Trapezoidal box 141 References Trusses Introduction Example 8.1: Truss efficiency 145 viii

4 strength ' 8.3. Member types Steel sections under axialload Joints in steelwork Example 8.2: Steel truss Enclosure Local loading of webs Continuous trusses High-strength steel 157 References 158 Arches Introduction Example 9.1: Composite arch Composite filled tubes in China Composite compression members Example 9.2: Composite tube arch Fabrication of curved sections Nodes in tubular structures Aesthetics Tied arches Example 9.3: Composite bowstring arch Arch buckling 177 References 183 Cable-stayed bridges Introduction Stay design Deck-stay connection Example 10.1: Composite cable-stayed bridge High-strength concrete Buckling interaction Shear connection Towers Tower top Example 10.2: Composite tower Stainless steel Strain-limited composite section (class 4) 202 References 203 Prestressed steel-concrete composites Introduction Displacement of supports Preflex beams Prestress using tendons 207 structures Design of prestressed composite Prestress losses Example 11.1: Prestressed composite girder Durability Prestressed composite box girders Corrugated webs Example 11.2: A structure with corrugated webs 213 ix

5 Extradosed bridges 214 References Assessment of composite bridges Introduction History Structure types Inspection Loads Example 12.1: A concrete-encased iron beam Materials Testing of the structure Analysis Incidental and partial composite action Cased beams Strengthening Life-cycle considerations Risk assessment Example 12.2: RIM analysis 228 References 230 Appendix a Approximate methods 231 Reference 232 Appendix b Calculation of elastic section properties 233 B.1. Section properties for steel sections 233 B.2. Section properties for steel-concrete composite sections 233 B.3. Section properties for cracked steel-concrete composite sections with reinforcement 234 Appendix c Section properties for the examples 235 Appendix d Appendix e Appendix f Calculation of plastic section properties for steel-concrete composite sections 237 Calculation of torsional properties for steel-concrete composite sections 239 Calculation of elastic section properties for double-composite sections 241 F.1. F.2. Section properties for uncracked double-composite steel-concrete composite sections 241 Section properties for cracked double-composite steel-concrete composite sections 242 Appendix G Moment-axial load interaction for compact steel-concrete composite sections 243 Index 245 x