Steel concreteandpositebridges
Part5.Codeofpracticefordesignofpositebridges
BritishStandardsInstitution
Contents
PageCooperating organizations Foreword 1Remendations Back cover1. 2. Soope References 2 23.1 3. Detinitions and symbols Definitions 2 23.2 4. Design philosophy Symbols Design:general 2 34.1 4.1.1 4.1.2 General Design loads due to shrinkage of concrete 3 34.1.3 4.2 Material properties Design loading effects 3 3 34.2.1 4.2.2 Structuralsteel General 34.2.3 Concrete reinforcement and prestressing steels 4 44.3 4.3.1 Limit state requirements General 4 44.3.2 4.3.3 Serviceability limit state Uttimate limit state 4 4o Design and detaiing of suporstructure for the serviceability limit state 45.1 5.1.1 Analysis of structure Distribution of bending moments and 45.2 vertical shear foroes Analysis of seotions 4 45.2.1 5.2.2 General Analysis 4 45.2.3 5.2.4 Effectivebreadthof concreteflange Dock slabsforming flangas of posite 45.2.5 beams Stoel section 5 95.2.6 5.3 Control of cracking in concrete Longitudinal shear 6 75.3.1 5.3.2 Shoarconnectors Design of shoar connection General 7 85.3.3 5.4 modified bycreep Temperature effects and shrinkage 125.4.1 5.4.2 General Tempereture effects 12 12 135.5 5.4.3 Shrinkage modified by creep Deflections 13 145.5.1 5.5.2 Calculation of deflections General 14 146. Design and cetaiing of suporstructure for the ultimate limit state 146.1 6.1.1 Analysis of structure General 14 146.1.2 Deck slabsforming the flanges of posite beams 146.1.3 6.1.4 Distributionof bendingmoments and Composite action 146.1.5 vertical shearforces Tomperature effects and shrinkage 146.2 doos Aqpeypou Analysls of sections 15 156.2.1 6.2.2 General Definitions 15 156.2.3 6.2.4 Analysis of pact cross soctions Analysis of slender cross sectioms 15 156.3.1 6.3 Longitudinal shear General 16 166.3.2 6.3.3 Transversereinforcemont Decksiab 16 166.3.4 7. Shearconnectors Composite box girders 18 187.1 General 18
Pago7.2 Effective span7.3 7.4 Effective breadth Distribution of bending moments and7.5 vertical shear forces Longitudinal shear7.5.1 7.5.2 Torsion Spacing of shear connectors Design of shearconnectors7.7 7.6 Composite plate Cased beams and fillerbeam8.1 8. construction Scope8.2 8.3 Analysis of structuro Limit staterequirements8.3.1 Transversemoments infiller beam8.4 8.4.1 Analysis of sections Servicoability limit state8.4.2 8.5 Longitudinal shear Ultimate limit state8.5.1 8.5.2 Senviceabllity limit state Ultimate limit state8.6 8.6.1 Temperature and shrinkage effects General8.6.2 8.6.3 Longitudinal stresses and strains Longitudinal shear8.7 8.7.1 General Controlof cracking8.7.2 8.7.3 Cased beams Filler beems8.8 '6 Design and construction Permanent formwork9.1 9.2 General Materials9.3 9.4 Design Temporary construction loading9.5 9.5.1 General9.5.2 9.5.3 Precastconcrete orposite precast Non-participating formwork Participating formwork 9.6 9.6.1 Design concrete permanent fommwork9 6.3 9.6.2 Interfaces Welding ofreinforcement9.6.4 10. Covertoreinforcement Theuse offriotion grip bolts as shear10.1 connectors in posite beams General10.2 10.2.1 Serviceability limit state Designrequirements:static loacing10.2.2 Ultimate lirmit state 10.3 Fatigue10.4 11. Other considerations Composite columns11.1 11.1.1 Scope General11.1.2 Materials 11.1.3 Shearconnection11.1.4 Concrete contributionfactor 11.1.5 Limits on slenderness11.2.2 Semi-empirical design method for 11.2 11.2.1 General Momonts and forces in columnsrestrained posite columns11.3.1 General 11.3 Analysis of column cross section11.3.3 Columns under uniaxial bendingabout 11.3.2 Axially loaded columns the minor axis
00hS*S8 1S8PART*5790h9h00 699h29
BS 5400 : Part 5 :1979
Page4.Page 11.3.4 Columns under uniaxial bending aboutEffective breadthratios forinternal the majoraxisrestralned from failure5.spans of continuous beams5 about the minor axis24Clear distance (mm) between bars in 11.3.5 Columns underuniaxialbending about6.tension for propped construction7 the majoraxis unrestrained against Clear distance (mm) between barsin failure about the minoraxis247.tension forunpropped construction7 11.3.6Columns under biaxial bonding24Nominalstatic strongths of shear 11.3.7 Ultimate strength of axially loadedconnectors fordifferentconcrete concrete filled circularhollow sections24strengths8 11.3.8Tensile cracking of concrete258.Propertiesof concroteflangefor 11.3.9Design detalls25calculation of temperature effects13 12.Infliuence of method of construotion9.Shrinkagestrainsand creepreduction andesign25factors13 12.1Sequence of construction2510.Maximum percentage redistribution of 12.2Permanent formwork25bonding moments at the ultimate 13.Prestressing in posite construction25limit state15 13.1General2511.Effective length of columns23 13.2Methods of prestressing2512.Values of constants Cand Cfor 13.3Limit state requirements25axially loaded concrete filled 13.4Prestressing the steel beam25ciroular hollow sections25 13.5Stress linitations in conorete attransfer2513.28 13.6Loss of prestress2613.1Values of coefficient K for column Appendices13.2curvea29 A. Calculation of effective breacithratios 27Values of coefficient forcolumn General27curveb29 A.113.3Values of coefficient K for column A.2 Equivalent simply supported spans27curvec30 A.3 Point loads not at midspan2714.Values of coefficient30 A4 Combination of loads27 B. Calculation of crack widths in posite Figures members271.Distribution of longitudinal stress in B 1 General27the concrete flange of a posite B.2 Formula forestimating crack widths due beam6 C. toflexure272.Shearconnectors9 Formulae and tablesfor the design3.Dimensions of haunches11 of posite columns284.Dimensions of specimens for test on C.1 CoofficientK 28shearconnectors11 C.2 CoufficientK305.Range of concrete mixes for which C.3 CoofficientKs31table 9 can be used14 C.4 Ultimate moment of resistance Mu of6.Sheerplenes and transverse posite columns31reinforcement17 Tables7.CoefficientK19 1.Values of the partial safety factor for8.Force diagrams forcalculating Mu33 materials ym9.Chartfor evaluating Mu ofconcrete 2.Effective breadith ratlios y for simply filled circuler hollow sections34 supported beams5 3.Effective breadth ratios y for cantilever beams9
Copyrig by the Brh Slandds hilon Sun Feb 09 15:45:55 2003
Britsh Standard
Steel concreteandposite ges
Part 5. Code.of practice for design of posite bridges
1.Scope
This Part of this British Standard supersedes CP 117: Part 2 and ougmentsthe provisions of BS 5400 Parts 3 4and 10 for struotural steel and reinforced or prestressed concrete when ponents of these meterials are sointerconneoted that they act positely.
It givesremendations for rolled or fabricated steelsectlons cased or uncased and forfiller beam systems. Consideratlonis given to simply supported and continuouseods psuno osqso problems of posite box boams. The remendationsaggregato cast in situ and precast concrete.Prestressing for the concrete olement cover normal and lightweightpositely with in situ concrete are also covered. and the use of permanent formwork designed to act
2. References
The titles of the standards publications referrod to in this Part of BS 5400 are listed in the inside beck cover.
3.Definitions and symbols
3.1 Definitions.Forthe purposes of this Partof this BritishStandard thefollowing definitionsand those givenin Part 1 apply.
3.1.1 cased posite beam. A beam posed ofeither rolled orbuit-up structural steel sections witha concrete encasement which acts in conjunction with aconcrete slab where the two elomonts are interconnectod so as to form a posite section.
3.1.2uncasedposite beam.Abeam posed of either rolled or built-up structural steel sections without aconcrete slab whoro the two elements are interconnecteds0 as to form a posite section.
3.1.3 posfte box beam. A steal box girder actingpositeiy with a concrete slab.
NOTElotxhcnstnthtlflngwheent in n open seee box the box is cloed by the concnete elab.
3.1 4 pogite colurn. A column posed eithar of ahollow steel section withan infill of concrete or of a steel section cased in concrete so that in elther case there isinteraction between steel and concrete.
3.1.5 posite plate.An in situ concrete slab castupon and acting positely with a structural steel plate.
3.1.6 concrete sfeb.The structural concrete slab thatwith the steel beams. The slab may be of precast cast in situ or posite construction.
3.1.7 posite slab An in situ concrete slab thatacts positely with structurally participating permanent
3.1.8participatingpermanent formwork.Formworkto in situ concrete when the strength of the formwork is
assumed to contribute to the strength of the positeslab.
3.1.9non-participating permanent formwork.Parmanent formwork that may or may not actpositely with the in situ concrete but where the formwork isneglected in calculating the strength ofthe slab.
3.1.10 filfer beam construction. Rolled or built-upsteel seetions that act in conjunction with a concrete slab and which are contained within the slab.
3.1.11.1 p/ete interaction. This implies that no slip occurs between the steel and the concrete slab orencasement.
3.1.11.2 partia/ interaction This implies that slip occurs atthe interface between steel and concrete and a discontinuity in strain occurs.
3.1.12 shear conmector. A mechanical device to ensure interaction between concrete and steel.
3.1.13 connector modlulus. The olastic shear stifness of a shear connectot.
3.2 Symbols. The symbols used in this Part of this standard have boen derived in accordance with appendix Fof CP 110 : Part 1 : 1972 and are as follows.
Ab in the bottom of the slab Cross-sectional area of transverse reinforcementAbs Abv Cross-sectional area of other transverse reinforcement in the bottom of the slah Cross-scctional area of additional transverseAc reinforcement Cross-sectional area of concreteA. Effective cross-sectional erea of trensverse reinforcementAt A Cross-sectional area of top flange of steel section Cross-sectional area of reinforcementAs Aat Cross-sectional area of the steel section Area of the encesed tension flange of theAs Area of tension reinforcement cross-sectional structural stoel memberarea of transverse relnforcement near the top of the slaba' at which the craok wiith is calculated Distance from the pression face to the pointDistance from the point considered to the surface of the nearest longitudinal barleteral dimension of a column Width of section or portion of fiange or leastbe Breadth of flange Effective breadth of portion of ffangeDs 0t Effective breadth of the posite section at thebw level of the tension reinforcement Half the distance betweon the contre lines ofC A constant (with appropriate subscripts) webs
Foreword 0OhS*S8 1S8 h 99h00699h296S*BS 5400is a document bining codes of practice to Part 8Romendations for meterials andcover the design and construction of steel concrete and posite bridges and specifications for loads materials workmanship concrete reinforcement and prestressing tendonsIt prises the following Parts: and workmanship. Part 9* Code of practico for bearings Part 10 Code of practice forfatigue.Part1Generalstatement In the drafting of BS 5400 importantchanges have beenPart 2 Specification forloads Part3* Codeof practicefordesignofsteel bridges made in respect of loading and environmental assumptions design philosophy load factors service stresses andPart4Codsof practice fordsignof concrete bridges design studies have been made on ponents and on structural analysisFurthermore recourse has been made to recenttheoretical and experimental research and severalPart 6Specification formaterials and workmanship. Part5Codeof practicefordesignofposite bridges experience of different bridge types is accumutated furtherPart7Specilication formaterials and workmanship modifications will be required.concrete reinforcement and prestressing tendons It should be noted thatthis Part of BS 5400 supersedes CP 117 : Part 2.
posite bridges requires the bined use of Part 5 and pgePart 3 of BS 5400.
Part 5 was published in 1979 the major decisions on scopeand approach having beentaken some years previously:some differenoes willexist between Part 3 and Part 5. Part3was published in 1982.It isnatural therefore that
designof steeworkinbridgeswitheithersteelorcncrete Part 3has been drafted on the assumption that for thedecks themethods of global analysis and all the proceduresin Part3.Forbeams Part 3may be used without any modification in conjunction with those provisions ofPart 5 that are applicable to the properties of theposite slab and its connection to the steel section.
