Design of Steel-Concrete Composite Bridges to Eurocodes Ioannis Vayas and Aristidis Iliopoulos CRC Press Taylor & Francis Croup Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Croup, an Informs business A SPON PRESS BOOK
Contents Foreword Preface Acknowledgments Authors xvii xix xxi xxiii 1 Introduction 1 1.1 General 1 1.2 List of symbols 2 2 Types of steel-concrete composite bridges 13 2.1 General 13 2.2 Composite bridges: The concept 14 2.3 Highway bridges 16 2.3.1 Plate-girder bridges with in situ concrete deck slab 16 2.3.2 Plate-girder bridges with semiprecast concrete deck slab 18 2.3.3 Plate-girder bridges with fully precast concrete deck slab 22 2.3.4 Plate-girder bridges with composite slab deck with profile steel sheeting 23 2.3.5 Plate-girder bridges with partially prefabricated composite beams 26 2.3.6 Double-girder bridges 27 2.3.6.1 Ladder deck bridges 29 2.3.7 Bridges with closed box girders 31 2.3.8 Open-box bridges 34 2.3.9 Arch bridges 40 2.3.10 Cable-stayed bridges 43 2.3.11 Suspension bridges 46 2.4 Railway bridges 47 2.4.1 General 47 2.4.2 Half-through bridges 48 2.4.3 Plate-girder bridges 49 2.4.4 Box-girder bridges SO 2.4.5 Filler-beam bridges 51 2.4.6 Pipe-girder bridges 51 vii
viii Contents 2.4.7 Arch bridges 51 2.4.8 Lattice girder bridges 52 2.5 Construction forms 52 2.5.1 General 52 2.5.2 Simply supported bridges 53 2.5.3 Continuous bridges 53 2.5.4 Frame bridges 54 2.5.5 Integral and semi-integral bridges 55 2.6 Erection methods 57 2.6.1 General 57 2.6.2 Lifting by cranes 57 2.6.3 Launching 57 2.6.4 Shifting 59 2.6.5 Hoisting 59 2.6.6 Segmental construction 59 2.7 Concreting sequence 59 2.8 Execution 61 2.9 Innovation in composite bridge engineering 62 References 63 3 Design codes 67 3.1 Eurocodes 67 3.1.1 General 67 3.1.2 EN 1990: Basis ofstructural design 69 3.1.3 EN 1991: Actions on structures 70 3.1.4 EN 1998: Design of structures for earthquake resistance 70 3.1.5 EN 1994: Design of composite steel and concrete structures 70 3.1.6 EN 1993: Design of steel structures 70 3.1.7 EN 1992: Design of concrete structures 71 3.2 National annexes 71 References 71 4 Actions 73 4.1 Classification of actions 73 4.1.1 Permanent actions 73 4.1.2 Variable actions 73 4.1.3 Accidental actions 73 4.1.4 Seismic actions 74 4.1.5 Specific permanent actions and effects in composite bridges 74 4.1.6 Creep and shrinkage 75 4.1.7 Actions during construction 75 4.2 Traffic loads on road bridges 75 4.2.1 Division of the carriageway 4.2.2 Vertical loads on the carriageway 76 4.2.2.1 Load model 1 (LM1) 76 4.2.2.2 Load model 2 (LM2) 78 into notional lanes 75
Contents ix 4.2.2.3 Load model 3 (LM3) 79 4.2.2.4 Load model 4 (LM4) 79 4.2.3 Vertical loads on footways and cycle tracks 80 4.2.4 Horizontal forces 80 4.2.4.1 Braking and acceleration forces 80 4.2.4.2 Centrifugal forces 81 4.2.5 Groups of traffic loads on road bridges 83 4.3 Actions for accidental design situations 83 4.3.1 Collision forces from vehicles moving under the bridge 83 4.3.1.1 Collision of vehicles with the soffit of the bridge, for example, when tracks are higher than the clear height of the bridge 83 4.3.1.2 Collision of vehicles on piers 83 4.3.2 Actions from vehicles moving on the bridge 83 4.3.2.1 Vehicles on footways or cycle tracks up to the position of the safety barriers 83 4.3.2.2 Collision forces on kerbs 85 4.3.2.3 Collision forces on safety barriers 86 4.3.2.4 Collision forces on unprotected structural members 87 4.4 Actions on pedestrian parapets and railings 87 4.5 Load models for 4.5.1 Vertical loads 88 4.5.2 Horizontal loads 88 4.6 Traffic loads on railway bridges 89 abutments and walls in contact with earth 88 4.6.1 General 89 4.6.2 Vertical loads 89 4.6.2.1 Load model 71 89 4.6.2.2 Load models SW/0 and SW/2 90 4.6.2.3 Load model "unloaded train" 91 4.6.2.4 Eccentricity of vertical loads (load models 71 and SW/0) 91 4.6.2.5 Longitudinal distribution of concentrated loads by the rail and longitudinal and transverse distribution by the sleepers and ballast 91 4.6.2.6 Transverse distribution of actions by the sleepers and ballast 92 4.6.3 Dynamic effects (including resonance) 92 4.6.4 Horizontal forces 95 4.6.4.1 Centrifugal forces 95 4.6.4.2 Nosing force 99 4.6.4.3 Actions due to traction or braking 100 4.6.5 Consideration of the structural interaction between track and superstructure 100 4.6.6 Other actions and design situations 102 4.6.7 Groups of loads 102 4.7 Temperature 103 4.7.1 General 103
x Contents 4.7.2 Uniform temperature component ATN 104 4.7.3 Temperature difference component ATM 105 4.7.4 Combination between ATN and ATM 106 4.7.5 Nonuniform temperature component ATK 106 4.7.6 Temperature effects during erection 106 4.8 Wind 108 4.8.1 General 108 4.8.2 Wind force in bridge transverse direction y 108 4.8.3 Basic wind velocity 109 4.8.4 Exposure factor 109 4.8.5 Force coefficient Cfy 0 110 4.8.6 Reference area Arcfy 110 4.8.7 Wind force in bridge vertical direction z 111 4.9 Earthquake 114 References 119 5 Basis of design 121 5.1 General 121 5.2 Limit state design 122 5.3 Ultimate limit state (ULS) 123 5.3.1 Design formats 123 5.3.2 Combination of actions 124 5.3.3 Safety factors and combination values 125 5.3.4 Basic combinations 129 5.3.5 Accidental combinations 131 5.3.6 Seismic combinations 132 5.4 Serviceability limit state (SLS) 133 5.5 Safety factors of resistances ym 140 5.6 Durability 140 5.6.1 Concrete cover 140 5.6.2 Structural steel 142 References 143 6 Structural materials 145 6.1 Concrete 145 6.1.1 Strength classes 145 6.1.1.1 Normal concrete 145 6.1.1.2 Lightweight concrete 146 6.1.2 Time-dependent deformations due to creep 147 6.1.2.1 General 147 6.1.3 Time-dependent deformations due to shrinkage 159 6.1.3.1 General 159 6.1.4 Time-dependent deformations due to time-dependent development of the modulus of elasticity of concrete 162
Contents xi 6.1.5 Time-dependent deformations due to hydration of cement 163 6.1.6 Cracking of concrete 164 6.1.6.1 General 164 6.2 Structural steel 172 6.2.1 Steel grades 172 6.2.2 Fracture toughness and through thickness properties 174 6.2.2.1 Material toughness 174 6.2.2.2 Lamellar tearing 178 6.2.3 Other material properties for structural steel 180 6.3 Reinforcing steel 180 6.4 Prestressing steel 181 6.5 Bolts 181 6.6 Stud shear connectors 181 References 182 7 Modeling and methods for global analysis 183 7.1 Global analysis models 183 7.1.1 Introduction 183 7.1.2 Beam models 183 7.1.2.1 Bridges with two main girders 183 7.1.2.2 Bridges with multiple main girders and stiff cross girders 184 7.1.2.3 Box-girder bridges 188 7.1.2.4 Bridges with two main girders and horizontal bracing between the lower flanges 196 7.1.3 Grillage models 199 7.1.3.1 General 199 7.1.3.2 Simply supported plate-girder bridges 199 7.1.3.3 Continuous plate-girder bridges 201 7.1.3.4 Skew bridges 204 7.1.3.5 Curved bridges 205 7.1.3.6 Box-girder bridges 205 7.1.4 3D models 208 7.1.4.1 General 208 7.1.4.2 Representation of steel and composite I girders 208 7.1.4.3 Slab representation 213 7.1.4.4 3D model implementation 215 7.1.4.5 Analysis during the concreting stages 218 7.1.4.6 Analysis at final stage 221 7.1.5 Models for other types of bridges 223 7.2 Effective width of wide flanges due to shear lag 223 7.2.1 General 223 7.2.2 Effective5 width of concrete flanges 225 7.2.3 Effective5 width of steel flanges 226 7.3 Cross-sectional properties 232
xii Contents 7.4 Effects of the theological behavior of concrete on structural systems 233 7.4.1 General 233 7.4.2 Creep in statically determinate systems 233 7.4.3 Creep and shrinkage in statically indeterminate systems 234 7.4.3.1 Creep due to movements of supports 237 7.4.3.2 Shrinkage 238 7.5 Models for slab analysis and design in transverse direction 242 7.5.1 General 242 7.5.2 Distributed permanent and variable loads 242 7.5.3 Wheel loads from traffic 244 7.5.4 Finite element models 245 7.6 Finite element models for global analysis 249 References 251 8 Buckling of plated elements 253 8.1 Introduction 253 8.2 Elastic critical stress 257 8.2.1 Introduction 257 8.2.2 Unstiffened panels 257 8.2.3 Stiffened panels 261 8.2.4 Stiffened and unstiffened panels: Combined loading conditions 271 8.3 Strength of plates 273 8.3.1 General 273 8.3.2 Postbuckling plate behavior: Plate buckling curves 274 8.3.3 Column-like behavior 278 8.4 Design by the reduced stress method 288 8.5 Effective width method 306 8.5.1 General 306 8.5.2 Unstiffened panels 306 8.5.3 Longitudinally stiffened panels 307 8.6 Member verification for axial compression and bending 309 8.7 Resistance to shear 311 8.8 Resistance to concentrated transverse forces 313 8.9 Interaction 317 8.9.1 Interaction N, M, V 317 8.9.2 Interaction N,M,FS 318 8.10 Flange-induced buckling 318 8.11 Design of stiffeners and detailing 319 8.11.1 Introduction 319 8.11.2 Intermediate transverse stiffeners in compression panels 319 8.11.3 Shear in transverse stiffeners 322 8.11.4 Torsional requirements for open section stiffeners 324 8.11.5 Discontinuous longitudinal stiffeners 325 8.11.6 Splices of plate sheets 326
Contents xiii 8.11.7 Cutouts in stiffeners 326 8.11.8 Transverse stiffeners 327 8.11.9 Web to flange welds 327 References 339 9 Ultimate limit states 341 9.1 Classification of cross sections 341 9.2 Resistance to tension: Allowance for fastener holes in bending capacity 350 9.3 Resistance of steel members and cross sections to compression 351 9.4 Resistance to shear due to vertical shear and torsion 354 9.5 Resistance to bending of steel cross sections 356 9.6 Interaction of bending with shear for steel cross sections 357 9.7 Class 1 and 2 cross sections 358 9.7.1 General 358 9.7.1.1 Sagging bending 358 9.7.1.2 Hogging bending 359 9.8 Cross sections with class 3 webs that may be treated as class 2 sections (hole-in-web method) 365 9.9 Class 3 cross sections 369 9.10 Class 4 cross sections that are treated as class 3 cross sections 375 9.11 Class 4 cross sections 396 9.12 Class 4 cross sections composed of the flanges 396 9.13 Lateral torsional buckling 398 9.13.1 Introduction 398 9.13.2 General method 398 9.13.3 Simplified method: Rigid lateral supports 401 9.13.3.1 Verification during concreting stages 401 9.13.3.2 Verification at hogging moment areas of continuous plate-girder bridges 403 9.13.4 Simplified method: Flexible lateral supports 408 9.13.5 Resistance and rigidity of supporting members 413 9.14 Design of the concrete deck slab 414 References 416 10 Serviceability limit states 417 10.1 Introduction 417 10.2 Stress analysis and limitations 417 10.2.1 Structural steel 418 10.2.2 Reinforcement 419 10.2.3 Concrete 420 10.3 Cracking of concrete 420 10.3.1 General 420 10.3.2 Minimum reinforcement 421
xiv Contents 10.3.3 Limitation ofcrack width 421 10.3.4 Thermal cracking during concreting (determination of cracked regions) 422 10.4 Web breathing 432 10.5 Deflections 433 10.5.1 General 433 10.5.2 Filler-beam decks 436 10.6 Vibrations 439 References 440 11 Fatigue 441 11.1 General 441 11.2 Fatigue resistance to constant amplitude loading 441 11.3 Fatigue resistance to variable amplitude loading 444 11.4 Detail categories 445 11.5 Fatigue load models and simplified fatigue analysis 449 11.6 Fatigue verification for structural steel 452 11.6.1 Simplified fatigue assessment 452 11.6.1.1 Road bridges 452 11.6.1.2 Railway bridges 456 11.6.2 Stress range and fatigue 11.6.2.1 Road bridges 457 assessment 457 11.6.2.2 Railway bridges 457 11.7 Fatigue verification for headed studs 461 11.7.1 General 461 11.7.2 Stress range and fatigue assessment 461 11.8 Fatigue verification for reinforcing 11.8.1 Fatigue assessment 463 steel 463 11.8.1.1 Road bridges 464 11.8.1.2 Railway bridges 465 11.8.2 Stress ranges 466 11.9 Fatigue verification for concrete 470 11.10 Possibilities of omitting fatigue assessment 471 11.11 Residual stresses and postweld treatment 484 References 485 12 Shear connection 487 12.1 Introduction 487 12.2 Resistance and detailing of headed stud shear connectors 488 12.2.1 General 488 12.2.2 Shear resistance of vertical studs 489 12.2.3 Tensile loading 489 12.2.4 Detailing ofshear connectors 491 12.2.5 Horizontal arrangement of studs 491
Contents xv 12.3 Longitudinal shear for elastic behavior 494 12.4 Longitudinal shear for inelastic behavior 501 12.5 Longitudinal shear due to concentrated forces 507 12.6 Longitudinal shear in concrete slabs 510 12.7 Shear connection of composite closed box bridges 516 References 518 13 Structural bearings, dampers, and expansion joints 519 13.1 General 519 13.2 Reinforced elastomeric bearings 520 13.2.1 General 520 13.2.1.1 Check of distortion 522 13.2.1.2 Check of the tension of the steel plates 524 13.2.1.3 Limitation of rotation 524 13.2.1.4 Stability 525 13.2.1.5 Safety against slip 525 13.2.2 Modeling for global analysis: Provision of seismic isolation 525 13.3 Spherical bearings 528 13.4 Pot bearings 528 13.5 Seismic isolation 529 13.5.1 High-damping reinforced elastomeric bearings 530 13.5.2 Lead rubber bearings 531 13.6 Anchorage of bearings 533 13.7 Calculation of movements and support reactions 534 13.8 Bearing schedules, support plans, and installation drawings 536 13.9 Fluid viscous dampers 544 13.10 Friction devices 545 13.11 Expansion joints 546 References 548 Index 551