August 2017
DESIGN MANUAL FOR ROADS AND BRIDGES
VOLUME 2 HIGHWAY STRUCTURES: DESIGN (SUB-STRUCTURES AND SPECIAL STRUCTURES) MATERIALS
SECTION 2 SPECIAL STRUCTURES
PART 1
BD 94/17
DESIGN OF MINOR STRUCTURES
SUMMARY
This Standard covers the design of minor highway structures, including:
• lighting columns;
• cantilevermastsfortrafficsignalsand/orspeedcameras;
• CCTV masts;
• fixedverticalroadtrafficsigns.
ItincorporatestheprovisionsofBSEN40,BSEN12899,andsupersedesBD94/07.
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DESIGN MANUAL FOR ROADS AND BRIDGES
Summary: This Standard covers the design of minor highway structures, including:• lightingcolumns;• cantilevermastsfortrafficsignalsand/orspeedcameras;• CCTVmasts;• fixedverticalroadtrafficsigns.ItincorporatestheprovisionsofBSEN40,BSEN12899,andsupersedesBD94/07.
Design of Minor Structures
BD 94/17 Volume 2, Section 2, Part 1
HIGHWAYS ENGLAND
TRANSPORT SCOTLAND
LLYWODRAETH CYMRUWELSH GOVERNMENT
DEPARTMENT FOR INFRASTRUCTURE NORTHERN IRELAND
August 2017
Registration of AmendmentsVolume 2 Section 2Part 1 BD 94/17
Amend No Page No Signature & Date of incorporation of amendments
Amend No Page No Signature & Date of incorporation of amendments
REGISTRATION OF AMENDMENTS
August 2017
Registration of AmendmentsVolume 2 Section 2
Part 1 BD 94/17
Amend No Page No Signature & Date of incorporation of amendments
Amend No Page No Signature & Date of incorporation of amendments
REGISTRATION OF AMENDMENTS
August 2017
DESIGN MANUAL FOR ROADS AND BRIDGES
VOLUME 2 HIGHWAY STRUCTURES: DESIGN (SUB-STRUCTURES AND SPECIAL STRUCTURES), MATERIALS
SECTION 2 SPECIAL STRUCTURES
PART 1
BD 94/17
DESIGN OF MINOR STRUCTURES
Contents
Chapter
1. Introduction
2. GeneralPrinciples
3. DimensionalLimitations
4. UseofBritishStandardsandStandardsIssuedby Overseeing Organisations
5. Design
6. FibreReinforcedPolymerCompositeLightingColumns
7. DoorOpenings
8. WallMountedBrackets
9. Attachments
10. FlangePlateConnectionsBetweenStructureandFoundation
11. Foundations
12. References
13. Approval
AnnexALimitStatesforCantileverMasts
AnnexBFatigueChecksofSteelStructuresandGuidanceforWeldClassification
AnnexCDetailedDesignofFlangePlates
AnnexDDeterminationofShapeCoefficientsbyTesting
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Chapter 1Introduction
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1. INTRODUCTIONGeneral
1.1 ThisStandardcoverstheuseoftherelevantparts(asdefinedherein)ofBSEN40forthestructuraldesignof:
• lightingcolumnsmadefromconcrete,steel,aluminium,andfibrereinforcedpolymercomposite(FRPCalsoknownasFRP);
• cantilevermastsfortrafficsignalsand/orsafetycameras(hereaftercalledcantilevermasts)madefrom steel;
• closedcircuittelevision(CCTV)mastsmadefromsteel;
• fixedverticalroadtrafficsign/signalposts;
• high masts;
• othermasttypestructures.
Notes:
(i) GuidanceandbackgroundinformationintheuseofBSEN40-3-1andBSEN40-3-3forthedesignoflightingcolumnsisgiveninPD6547:2004.
(ii) ThisStandardcoverstheuseofTheInstitutionofLightingProfessionalsProfessionalLightingGuide07,HighMastsforLightingandCCTV,2013Edition,Sections1and2(ILPPLG07)forthedesignofCCTVmasts.ThisGuidewasoriginallydevelopedforhighmastlightingandhasbeenrevisedtoincludeCCTVmastsastheyhavesimilarfeatures.
(iii) RequirementsforthedesignoffixedverticalroadsignsaregiveninBSEN12899:Part1.TheserequirementsaresupplementedbythisStandard.
ItsetsouttheOverseeingOrganisation’sparticularrequirementswheretheseaugment,orareadditionaltothosegivenintheBritishStandard.Inaddition,theStandardgivestherequirementsforlightingcolumnsmadeessentiallyfromglassfibrereinforcedplastic(FRPorFRPC).ThetechnicalbasisfortheclausesonFRPCislimitedanditmaybecomenecessaryinduecoursetoreviewtherequirements,onthebasisoftheirperformanceinservice.
Wherematerialsotherthanconcrete,steel,aluminiumorFRPCareusedforotherminorstructuresadeparturefromstandardsshallbesoughtfromtheTechnicalApprovalAuthority.
Scope
1.2 ThisStandardsetsoutthestructuraldesignrequirementsforthefollowingminorhighwaystructuresforuseontrunkroadsincludingmotorways:
• lightingcolumnsandwallmountedbracketsmadefromconcrete,steel,aluminium,concreteandFRPC,includinglightingcolumnsmountedonotherstructures,e.g.onbridges;
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• steelCCTVmastsmountedonfoundationsintheground.TherequirementsforCCTVmastsmountedonotherstructureseggantriesareoutsidethescopeofthisStandard;
• cantilevermastsmadefromsteelfortrafficsignalsand/orspeedcameras.ThisStandardexcludesthedesignrequirementsforpermanentandtemporarycantileversignandsignalgantriesforwhichBD51(DMRB2.2.4)shallbeused;
• fixedverticalroadtrafficsign/signalposts.ThisStandardexcludestheelectronicdesignrequirementsofcertaintrafficsigns,asdefinedinBSEN12899-Part1;
• high masts;
• othermasttypestructures.
Notes:
(i) ThestructuralrequirementsforlatticestructuresareoutsidethescopeofthisStandard;refertoBSEN1993-3-1:2006oranyotherrelevantstandard.
(ii) ThestructuralrequirementsforpassivelysafestructuresshouldcomplywiththisStandardbutthepassivesafetycharacteristicsofsuchstructuresaredealtwithinEN12767.
(iii) InNorthernIrelandthisStandardappliestominorstructuresonallclassesofroad.
Mutual Recognition
1.3 Wherethereisarequirementinthisdocumentforcompliancewithanypartofa“BritishStandard”orothertechnicalspecification,thatrequirementmaybemetbycompliancewith:
(a) astandardorcodeofpracticeofanationalstandardsbodyorequivalentbodyofanyEEAstateorTurkey;
(b) anyinternationalstandardrecognisedforuseasastandardorcodeofpracticebyanyEEAstateorTurkey;
(c) atechnicalspecificationrecognisedforuseasastandardbyapublicauthorityofanyEEAstateorTurkey;or
(d) aEuropeanTechnicalAssessmentissuedinaccordancewiththeproceduresetoutinregulation(EU)No305/2011;
providedthattherelevantstandardimposesanequivalentlevelofperformanceandsafetyprovidedforbythestatedStandardortechnicalspecification.
“EEAState”meansastatewhichisacontractingpartytotheEuropeanEconomicAreaAgreement.
“BritishStandard”meansanystandardpublishedbytheBritishStandardsInstitutionincludingadoptedEuropeanorotherinternationalstandards.
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Implementation
1.4 ThisStandardshouldbeusedforthwithonallschemesfortheconstructionandimprovementoftrunkroads,includingmotorways,currentlybeingprepared,providedthat,intheopinionoftheOverseeingOrganisation,thiswouldnotresultinsignificantadditionalexpenseordelayprogress.DesignOrganisationsshouldconfirmitsapplicationtoparticularschemeswiththeOverseeingOrganisation.WheretheOverseeingOrganisation’scontractdocumentsarebasedontheSpecificationforHighwayWorks(MCHW1)useofthisStandardismandatory.InNorthernIrelandthisstandardshouldbeusedonallroads.WherethisStandardduplicatesorcoversrequirementsinexistingstandardsduringaperiodofco-existence,itshalltakeprecedenceunlessotherwiseagreedwiththeOverseeingOrganisation.
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Chapter 2General Principles
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2. GENERAL PRINCIPLESSiting
2.1 ThesitingofminorstructuresshallaccordwiththeTDsandTAsasshowninTable1asrelevanttothestructureconsidered.Thisshallincludeconsiderationofvisibilitybytheapproachingtraffic.
TD9 TD18 TD19 TD23 TD33 TD34 TA74Lightingcolumns ü ü ü ü ü
Cantilever masts ü ü ü ü ü
CCTV masts ü ü
Roadtrafficsigns ü ü ü
Othermasttypestructures
ü * ü ü * ü ü
Table 1: TDs and TAs
Note:Wherepossiblecantilevermastsshouldnotbelocatedonunder-bridges.*thesemaybeapplicabledependingontypeofmast.
Layout
2.2 AllelementsofminorstructuresshallcomplywiththeclearancesspecifiedinTD27(DMRB6.1.2)afterallowingfordeflectionsduetodead,live,windandHighVehiclebuffetingloads.
2.3 Theclearnewconstructionheadroomforroutesotherthanhighloadroutesshallbe5,700mmminimum,asdefinedinTD27Table8(DMRB6.1.2)forFootbridgesandSign/SignalGantries.Wherecantilevermastsaresitedonhighloadroutes,theclearnewconstructionheadroomshallbe6,450mmminimum,asdefinedinTD27Table8(DMRB6.1.2).Inadditiontostructuraldeformations,considerationshallbegiventosettlementwhencalculatingheadroom.
2.4 RequirementsforthevehiclerestraintsystemshallbeagreedwiththeTechnicalApprovalAuthority.ThesetbackofthevehiclerestraintsystemtotheedgeofthecarriagewayshallbeinaccordancewiththerequirementsoftheOverseeingOrganisation.Wherepassivelysafesignposts,lightingcolumnsortrafficsignalpostsareprovided,inaccordancewithTD89/08,furthervehiclerestraintsystemsshallnotberequired,unlessrequiredbytheexistenceofotherhazards.
2.5 TheclearancefromthefrontofthevehiclerestraintsystemtothefaceoftheminorstructureshallbeselectedfromtheWorkingWidthgiveninBSEN1317,Part2,orotherrelevantstandards.
Protection for Road Users and Structure
2.6 CantilevermastsandCCTVmastsshallbelocatedeither:
(i) morethan4.5metresfromthe‘Pointfromwhichset-backismeasured’,asreferredtoinTD19(DMRB2.2.8);or
(ii) onaslopesuchthattheundersideoftheflangeplateismorethan2metresverticallyabovetheedgeofthecarriagewayclosesttothepost;or
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(iii) behindasafetybarrierconformingtotherequirementsofTD19(DMRB2.2.8)andanappropriateworkingwidth.
PositioningofcantilevermastsandCCTVmastsinotherlocationsshallbesubjecttotheapprovaloftheTechnicalApprovalAuthority.
2.7 WherethepostofthecantilevermastorCCTVmastislocatedbehindavehiclerestraintsystemmeetingtherequirementsofBSEN1317:Part2,furthervehiclerestraintsystemsarenotrequired.
Equipment
2.8 Allluminaires,lanterns,brackets,signs,trafficsignals,speedcamerasandassociatedequipmentshallbesecurelyattachedtothestructureusingvibrationresistantfixingsstrongenoughtowithstanddesignloads.Thestructuraldesignshallmakeadequateprovisionfortheattachmentofequipmentandshallconsiderredundancy.(i.e.canthefailureofasingleitem,likeabolt,causethefailureoftheentiresystem?)AnysubsequentmodificationstostructuralmembersshallonlybecarriedoutwiththeapprovaloftheTechnicalApprovalAuthorityinaccordancewithBD2(DMRB1.1.1)(refertoChapter4).
In-Situ Connections
2.9 Insituconnectionsofmainstructuralmetalelementsshallbebymeansofbolts.Ifotherformsofin-situconnectionareproposedthentheirstaticandfatiguedesignstrengthshallbecalculatedfromfirstprinciplesandshallbeagreedwiththeTechnicalApprovalAuthority.Alternatively,thedesignstrengthmaybebasedontheresultsoffull-scaleloadtests,subjecttotheagreementoftheTechnicalApprovalAuthority.
Identification
2.10 InEnglandandWalesthestructuresiteidentificationmarkingshallbeinaccordancewithBD45(DMRB3.1.1).InScotland,TransportScotlandshallbeconsultedwhilstinNorthernIrelandtheRoadsServiceshallbeconsulted.
Wherenotreadilyidentifiablebythedesign,structuresthathavebeendesignedtobepassivelysafetoBSEN12767shallbemarkedtodifferentiatethemfromothertypesofstructures.Themarkingsystemwillincorporatethephrase“CrashFriendly”andbeplacedonthepostorcolumninapositionthatwillnotaffectthefunctionalityofanypartoftheassemblyortheidentificationmarksrequiredbyBD45(DMRB3.1.1).TheformofmarkingappropriateforindividualproductsshallbeagreedwiththeOverseeingOrganisation.
Use of Dissimilar Metals
2.11 Wheredissimilarmetalsaretobeused,theconnectionsshallbedesignedtoavoidtheriskofgalvaniccorrosion.Theelectricalbondingofallmetalcomponentsshallnonethelessbemaintained.
Protection Against Corrosion
2.12 SurfacepreparationandpaintprotectionofsteelshallcomplywiththerelevantclausesoftheSeries1900intheSpecificationforHighwayWorks(MCHW1).
2.13 Formaterialsotherthansteelitshallbedemonstratedthattheywillhavealifeexpectancygreaterthantheservicelife.(e.g.galvaniccorrosionofaluminiumduetolocalgroundconditionsandUVdegradationofFRPCcolumns).
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Chapter 3Dimensional Limitations
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3. DIMENSIONAL LIMITATIONSLighting Columns
3.1 ThedimensionalrequirementsforlightingcolumnsaregiveninBSEN40-2.Theoveralldimensionallimitations for the lighting columns covered by this Standard shall be:
Forsteel,aluminium,FRPCandconcretecolumns:
(i) posttopcolumns <20mnominalheight
(ii) columnswithbrackets <18mnominalheight
(iii) bracketprojections -notexceedingthelesserof0.25xnominalheightor3metres.
Note:NominalheightsandbracketprojectionsaredefinedinBSEN40-2:2004.
CCTV Masts
3.2 ThenominalheightofsteelCCTVmastscoveredbythisStandardshallbelessthanorequalto25m.Thenominalheightistakenastheverticaldistancebetweentheundersideoftheflangeplateandthetopofthemast.
Note:Thenominalheightexcludestheheightofcamera,mountingetc(refertoFigure1).
3.3 ThedesignheightofaCCTVmastshallbetakenastheverticaldistancebetweentheundersideoftheflangeplateandthetopoftheCCTVmastorcamerainitsoperatingposition,orotherattachments,whicheverisgreater.
Note:The“designheight”isdifferenttothe“nominalheight”andisrequiredforwindloadingcalculations(refertoFigure1).
Notes:ThedefinitionsgiveninILPPLG07,Section1.4shouldbeinterpretedasfollows:
(i) HIGHMASTshallalsorefertoCCTVmasts,meaningthesupportintendedtoholdoneormoreCCTVcameraswiththeirmountingsandhousings.
(ii) ThetermLUMINAIREshallbetakenasincludingCCTVcameras,theirmountingsandhousings.
(iii) ILPPLG07maybeusedinthedesignofCCTVmastslessthan10minheight.
Cantilever Masts
3.4 Forcantilevermasts,asshowninFigure1:
(i) NominalHeight<8.5m
Wherenominalheightistakenasthedistancebetweentheundersideoftheflangeplateandthehighestpointonthemast.(SeeFigure1.)
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(ii) CantileverProjection<8.5m.
(iii) Thehorizontalprojectedareaofanysigns,trafficsignals,speedcamerasandassociatedequipment,suspendedabovethecarriagewayshallnotexceed1.2m2andtheverticalprojectedareashallnotexceed0.3m2.
Traffic Sign/Signal Posts
3.5 Thenominalheightoftrafficsign/signalpostsshallbe<9m.
Note:Abovethisheightdynamicfactorsandfatigueshallbeconsidered.
Other mast type structures
3.6 ThenominalheightofothermasttypestructuresshallbeagreedwiththeOverseeingOrganisationbasedontherequiredenduseusingtheabovelimitationsasguidance.
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Figure 1 General Arrangement of Cantilever Mast and CCTV Mast and Structural Deformations
of Cantilever Masts (see Table A2)
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Chapter 4Use of British Standards and Standards Issued by the Overseeing Organisations
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4. USE OF BRITISH STANDARDS AND STANDARDS ISSUED BY THE OVERSEEING ORGANISATIONS
4.1 Thedesignofminorstructuresshallcomplywiththefollowing:
• Lightingcolumnsandcantileversignalmasts–therelevantpartsofBSEN40.
• CCTVmasts–ILPPLG07.
• Roadtrafficsignposts–BSEN12899-1.
AllasimplementedbythisStandardandbytheSpecificationforHighwayWorks(MCHW1),hereinafterreferredtoas“thespecification”.
4.2 Themanufactureandinstallationofminorstructuresshallcomplywiththerelevantrequirementsoftheharmonisedstandards.Whereproductsarebeingmanufacturedfollowingtheprincipleofastandardbutareforproducts,orapplications,notfullycoveredbythatstandard,orwheretheproductisnotcoveredbyaharmonisedstandardthentherequirementssetoutwithintheSpecificationforHighwayWorksmustbefollowed.Proposalstousematerials,methodsorproceduresnotcoveredbythisshouldbeagreed.
4.3 ThespecificOverseeingOrganisation’sproceduresfortheTechnicalApprovalofminorstructuresforuseonmotorwaysandothertrunkroadsaregiveninBD2(DMRB1.1.1).
Note:InNorthernIrelandtheproceduresapplytominorstructuresonallclassesofroad.
4.4 MinorstructuresinveryexposedareasshallbeclassifiedasCategory1inaccordancewithBD2(DMRB1.1.1).
4.5 WithintheUnitedKingdom,veryexposedsitesaredefinedas:
(a) sitesathighaltitude,above250m;
(b) siteswithin5kmfromthecoast;and
(c) sitessubjecttosignificantlocalfunnelling.
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Chapter 5Design
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5. DESIGNGeneral Requirements
5.1 Minorstructuresshallbedesignedinaccordancewiththerelevantrequirementsofthestandardslistedinparagraph4.1,asimplementedbytheSpecificationforHighwayWorks(MCHW1)andbythisStandard.
Structural Criteria
5.2 Thedesignlifeshallbe25years,unlessotherwiserequiredbytheTechnicalApprovalAuthority.
Limit States
5.3 Minorstructuresshallbedesignedtosatisfytherelevantultimatelimitstatesandtheserviceabilitylimitstate,including,forsteelstructures,meetingfatiguecriteria.
Lighting Columns:
5.4 ForlightingcolumnsthepartialsafetyfactorsandcriteriaforserviceabilityandultimatelimitstatesshallbetakenasClassBasgiveninBSEN40-3-3.
Thehorizontaldeflectionsofeachlanternconnectionshallconformtoclass2asspecifiedinBSEN403-3Table3.
CCTV Masts:
5.5 ForCCTVmaststhepartialsafetyfactorsandcriteriaforserviceabilityandultimatelimitstatesshallbeasgiveninILPPLG07,Clauses2.4and2.5.
ILPPLG07Clause2.3.2.3setsoutsomedeflection/rotationlimitsthataregreaterthanthoseusedpreviously.Thelimitsbelowshouldbeused.
ForCCTVapplicationsthemaststiffnessshallbesuchthatwithloadsarisingfromagustwindprofile,withawindspeedof22m/secat10mabovegroundlevel,thetorsionalrotationatthetopofthemastshallnotexceed25minutesofarc(0.0073radians)andthelineardeflectionatthetopofthepoleshallnotexceed150mm.
ThedesignershallconfirmthattheoperationaluseoftheCCTVcameraswillnotbeaffectedbytheproposedlimits.
Note:Fortheserviceabilitylimitstate:
(i) AddattheendofILPPLG07Section2.3.2.3:“ThiscalculationshalltakefullaccountoftheactualweightsoftheCCTVmast,cameras,mountings,housingsandanyotherattachments.TheOverseeingOrganisationmaydefinemorestringentrotationanddeflectioncriteriaifrequired”.
(ii) Vehiclecollisionloadsdonotneedtobeconsideredbecauseoftherequirementsimposedbyclause2.6.
Cantilever masts for traffic signals and/or speed cameras:
5.6 Cantilevermastsfortrafficsignalsand/orspeedcamerasshallmeetthecriteriaof5.6.1to5.6.3.
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5.6.1 ThreelimitstatesarespecifiedinTableA1ofAnnexAofthisStandardwithvaluesofthepartialfactorγF given;thesecoverstrength,fatigueanddeflection.WhereanypermanentloadhasarelievingeffectγF shall betakenas1.0inboththeultimatelimitstateandserviceabilitylimitstate.
Note:Vehiclecollisionloadsshallnotbeconsidered.
5.6.2 Intheserviceabilitylimitstateunderloadingcombination1,thedeflectionsandrotationsduetowindloading onlyshallbelimitedsuchthatthedeformationsdonotexceedthevaluesgiveninTableA2ofAnnexA*.
*Morestringentdeflectionlimitsshallbenecessarywhentheperformancerequirementsoftheequipmenttobemountedsorequirethem.
5.6.3 Thedeformationattheextremitiesofthestructuralsupportshallbederivedfromthesumofthecomponentsoftheeffectsoftheloadinthesupportposts,cantileverandsignsupports,[seeFigure1].
Road Traffic Sign Posts:
5.7 ForroadtrafficsignpoststhepartialsafetyfactorsandcriteriaforserviceabilityandultimatelimitstatesaregiveninBSEN12899-1andtheUK’sNationalAnnex.
Minimum Thickness of Steel Sections for Cantilever Masts
5.8 Theminimumthicknessofstructuralsteelsectionsusedincantilevermastsshallbeasfollows:
(i) platesandsectionsotherthanhollowsections: 6mm
(ii) hollowsectionseffectivelysealedbywelding,otherthanasmall drainholewithadiameterofbetween10mmand15mm: 5mm
Closed Hollow Sections for Cantilever Masts
5.9 Steelhollowsectionsusedincantilevermastsshallbedesignedtoresisttheingressandretentionofwaterormoisturebygravityflow,capillaryactionorcondensation.Theplatesusedtoclosetheopenendsofhollowsectionsshallbeofthicknessnotlessthanthelesserofthefollowing:
(i) thethicknessofthewallsofthehollowsection;
(ii) 8mm.
TheendplatesshallbejoinedbycontinuousstructuralqualityweldingtoBSEN1011:Parts1and2.Shouldtherebeapossibilityofwaterenteringandsubsequentlyfreezing,thendrainholesshallbeprovided.Thesizeoftheholeshallbeappropriatetothevoidbeingdrained,butshallnotbelessthan10mmorgreaterthan15mmdiameter.Hollowsectionsinnon-corrosiveorgalvanisedsteelshallbeprovidedwithsuchdrainholesatalllowpoints.
Fatigue Criteria for Steel Structures
5.10 Therulessetoutin5.10to5.16shallbeusedforsteellightingcolumns9mandaboveinheightandtoallsteelcantilevermasts.Theserulesmaynotbeapplicabletoveryexposedsites;insuchcasesthedesignshallbesubjectedtoTechnicalApprovalproceduresassetoutin4.3.Structuresinmaterialsotherthansteel are not covered by the fatigue rules in this Standard and in such cases the design shall be subjected to TechnicalApprovalproceduresassetoutin4.2.
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Inallcasestheprocedurestobeusedforfatigueassessmentshallbeagreedbetweenthedesigner,theclientandtheOverseeingOrganisation,see4.2above.
5.11 ThestringentdeflectionrequirementsforthedesignofCCTVmastsmeanthatstressrangesinducedbydynamicresponsetowindloadingarelikelytobelow.Thusfatigueisunlikelytobeacriticaldesignconditionprovidedsuitabledetailsareused.HoweverforCCTVmastssitedinveryexposedlocations,asdefinedin4.4fatigueshallbeconsidered.
5.12 Fatiguedamageismostlikelytooccuratoradjacenttoweldsornearsharpcornerscreatingstressconcentrations;particularlyvulnerablepositionsare:
(i) flangeplates:
• attheweldthroatbetweenthecolumnandflange;
• intheparentmetaladjacenttotheweld;
(ii) dooropenings:
• at welded attachments;
• atpoorlyfinishedcutedges;
(iii) atanystiffeningbetweenthecolumnandtheflange;
(iv) shoulderjoints:
• at the weld throat;
• intheparentmetaladjacenttotheweld.
Atsuchpositions,fatiguepronedetailsshouldbeavoided.
5.13 Fatigueiscriticallydependentongeometricalconfigurationsandfabrication.StiffenedandunstiffeneddooropeningsshouldcomplywiththeconstraintsshowninFigure2.Inadditionthefollowingfabricationconstraints should be met:
(i) sharpirregularitiesatfreeedgesduetotheflamecuttingprocessshouldbegroundout;
(ii) noweldingshouldbecloserthan10mmfromtheedgeoftheunstiffeneddooropening;
(iii) longitudinaledgestiffenersshouldbecontinuousovertheirfullextent.
(ix) Whereshoulderjointsareused,theyshouldhaveanangleofinclinationtotheaxisofthecolumnofbetween12°and35°.(SeeFigure3whichshowsatypicalshoulderjoint).
5.14 Generally,whenundertakingfatiguechecksnominalstressesshouldbeusedbasedonnominalsectionproperties.Thestressconcentrationsinherentinthemake-upofaweldedjoint(arising,forexample,fromthegeneraljointgeometryandtheweldshape)aregenerallytakenintoaccountintheclassificationofthedetails.Otherwisethenominalstressesshouldbemultipliedbystressconcentrationfactorsderivedfromstressanalysisofthejointorfrompublisheddata.
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5.15 Inordertoundertakeafatiguecheckitisnecessarytodeterminealoadingspectrafromwinddataappropriatetothesite.Intheabsenceofsuchdata,thefatigueloadingprovisionsgiveninAnnexBmaybeadopted.
5.16 Classificationmaybederivedbyfatiguetestingofasampleoftypicalfull-scaledetailsinanindependenttestinglaboratoryandcoveringanappropriatestressrangetoenableafatiguelifecurvetobederived.Sufficienttestsshouldbeundertakentoprovideadesigncurverepresentingmeanminus2standarddeviations.
5.17 Intheabsenceofdataonfatiguelifecurvesandloadingspectra,theproceduresetoutinAnnexBshallbefollowed.
Determination of Shape Coefficients
5.18 Wherewindtunneltestsarenecessaryforthedeterminationofshapecoefficientsforcolumns,bracketsandlanterns,thetestingshallbecarriedoutinaccordancewithAnnexDofthisStandard.
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Figure 2 Door Openings
No
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Figure 3 Typical Shoulder Joint
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Chapter 6Fibre Reinforced Polymer Composite Lighting Columns
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6. FIBRE REINFORCED POLYMER COMPOSITE LIGHTING COLUMNS
Design
6.1 Loading.DesignloadsandmomentsshallbedeterminedinaccordancewithBSEN40-3-1andBSEN40-7asimplementedbythisStandard.
6.2 ThefactorβforthedynamicbehaviouroftheFRPCcolumnshallbedeterminedbyreferencetoBSEN40-7:AnnexB:FigureB.1.
Verification of Structural DesignGeneral
6.3 ThestructuraldesignofFRPCcolumnsshallbeverifiedeitherbycalculationsorbytesting.Thetestresultstakeprecedenceinallcases.
Calculations
6.4 DesigncalculationsforFRPCcolumnsshallbeinaccordancewiththerequirementsBSEN40-7.
6.5 ThemechanicalpropertiesoftheFRPmaterialtobeusedinthestructuraldesigncalculationsshallbedeterminedfromtestsusingflatsheetsamplesmanufacturedinthesamemannerasthatproposedfortheproductioncolumn.FlexuralstrengthandthemoduliinbothlongitudinalandtransversedirectionsshallbedeterminedtogetherwiththeshearmodulusandthePoisson’sratio,δ12.Astatisticalassessmentshallbemadeoftheresultstodetermine95%confidencelimitsofthevaluestobeused.
Use of Other Materials
6.6 AllothermaterialsincorporatedintheFRPcolumnsshallcomplywiththeSpecificationandtherelevantpartsofBSEN40.
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Chapter 7Door Openings
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7. DOOR OPENINGS7.1 Wheredooropeningsarerequired,thesizesgiveninTable2shouldbespecifiedwhenproviding
informationforAppendix13/1oftheSpecification.
7.2 AlternativedooropeningsselectedfromthesizesgiveninBSEN40-2maybeused,providedtheyareshowntobeadequateforthesizeofequipmenttobehousedandmaintained,inthecolumn.
7.3 Columnsmountedonstructuresorinsituationswherethereisariskthatadetacheddoorcouldcauseanaccidentifitfellontheareabelowshallhavetheirdoorshingedorheldcaptivebyanapprovedmetalchainorstrapwhichshallbesufficientlyrobust,tosupportthedoorinseveregaleconditions.
7.4 Wherethesectioncontainingthedooropeningissteeloraluminiumandcircularorpolygonalwitheightormoresides,designstrengthsshallbecalculatedinaccordancewithBSEN40-3-3.Inallothercasesthedesignstrengthshallbecalculatedfromfirstprinciples.Alternatively,thedesignshallbebasedontheresultsoffull-scaleloadtests.Inallsuchcasestheprocedurestobeusedshallbeagreedbetweenthedesigner,theclientandtheOverseeingOrganisationsee4.2above.
Nominal column height (h) in meters
Type of door Door opening for metal columns
(height x width) (mm)
Door openings for concrete columns (height x width)
(mm)5 and 6 single door 500x100 680x95
8,10and12 single door 600x115 680x130
8,10and12 extendedsingledoor – 900x130
8,10and12 double doors 500x120 or600x115each
–
Table 2 Door Opening Sizes
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8. WALL MOUNTED BRACKETS8.1 Wallmountedbracketsshallbedesigned,inaccordancewiththerelevantrequirementsforcolumn
brackets.Thebracketshallbefixedtoitssupportbymeansofaflangeplateandanchoragewhichshallbedesignedinaccordancewithparagraph10.9.
8.2 Thewallonwhichthewallmountedbracketsarefixedshallbecapableofcarryingtheadditionalloadsandotherforcesthatmaybetransmittedbythebracket.Thedesignerofthebracketshallprovidethenecessaryloadsforotherstoassesstheadequacyofthewall.
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Chapter 9Attachments
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9. ATTACHMENTSGeneral Requirements
9.1 Minorstructures,otherthanCCTVmasts(see9.6to9.8below)andfixedtrafficsign/signalposts(seeEN12899-1)shallbedesignedfortheattachmentgiveninparagraph9.2.Attachmentsshallnotbeallowedoncantilevermasts.
9.2 Theattachmentshallbetakenasasign,detailsofwhichshallbe:
(i) Thesignshallbetakenasrectangularinelevation,withasurfaceareaof0.3m2.
(ii) Theeccentricityfromthecentrelineofthecolumntothecentreofareaofthesignshallbetakenas300mm.
(iii) Theheightabovegroundlevelatthecolumntothecentreofareaofthesignshallbetakenas2500mm.
(iv) Theorientationofthesignshallbeselectedtoproducethemostadverseeffectsforthedesignconditionbeingconsidered.
9.3 TheforcesduetodeadandwindloadsonthesignandbracketprojectingfromthecolumnshallbedeterminedinaccordancewithBSEN40-3-1.Theshapecoefficientofthesignshallbetakenas1.8unlessderivedfromBSEN1991-1-4forthespecificshapeandaspectratioofthesign.
9.4 Wherelargersigns,wastepapercontainers,flowerbasketsetc,aretobeattached,thecolumnshallbedesignedtoresisttheadditionalloadings.Whereappropriatetheadditionalloadingsshallbecalculatedinaccordancewithparagraph9.3.
9.5 Minorstructuresdesignedtocarryattachmentsgreaterthanthosedefinedin9.2shallhaveidentifyingmanufacturer’sfeaturesormarkstoenablethemtobeclearlyandunambiguouslyidentifiedthroughouttheirservicelife.TheuniqueidentifyingmarkshallbelistedasrequiredbyBD62(DMRB3.2.1).AllotherrequirementsfortheidentifyingmarkshallbeasrequiredintheSpecification.(See4.1).
Attachments to CCTV Masts
9.6 CCTVmastsshallnotbedesignedforattachmentsotherthanCCTVcamerasandtheirassociatedequipmentunlessotherwisespecified.WhereattachmentsarespecifiedtheyshallbeincorporatedintothedesignoftheCCTVmastsinaccordancewiththefollowingprovisions:
9.7 Whereattachmentsaretobeused,themastshallbedesignedtoresisttheadditionalloading,whichshallbedescribedinAppendix13oftheNotesforGuidanceontheSpecification(MCHW2).WhereappropriatetheadditionaldeadandwindloadsshallbecalculatedinaccordancewithILPPLG07.
9.8 WhereattachmentsarerequiredtheCCTVpoleandtheattachmentsshallbedesignedsuchthattheoperationoftheCCTVcameraisnotimpeded.Similarly,accessforinstallation,inspectionormaintenanceofanattachmentshallnotinterferewiththeoperationoftheCCTVcamera.Whereattachmentsarelocatedbelowtheoperatingpositionofthecamera,theyshallbedesignedasdemountabletoallowtheCCTVmountingtoberaisedandlowered.
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10. FLANGE PLATE CONNECTION BETWEEN STEEL STRUCTURE AND FOUNDATION
General
10.1 Wherefoundationsconsistofreinforcedconcrete,theconnectionbetweenthestructureanditssubstructureshallbedesignedinaccordancewithclauses10.2to10.24asappropriate.
10.2 Astructurewithaflangeplateshallbefixedtothefoundationorbridgedeckbyanattachmentsystemandanchoragewhichshallbecapableofprovidingtherequiredrestraint.Thiswillusuallytaketheformofholdingdownboltswhichconnectwithananchorage.AnchoragesofexpandingtypeshallnotbeusedunlesstheirlongterminsituperformanceunderfatigueloadingcanbedemonstratedtothesatisfactionoftheTechnicalApprovalAuthorityandtheOverseeingOrganisation.Theattachmentsystemshallallowthestructuretobedemounted,or,forlightingcolumns,besuchthatremovalandreplacementofdamagedlightingcolumnsmaybereadilyachieved.
Note1:Theproceduregivenin10.4to10.21isbasedontheflangeplateanditsconnectionsbeingdesignedtoresistvehicleimpact.Forminorstructuresthatsatisfytherequirementsofclauses2.6(i),2.6(ii)or2.6(iii)designagainstvehicleimpactisnotrequired.Insuchcasestheflangeplateanditsconnectionsshallbedesignedfordeadloadandwindloadsonly.ThisshallbeachievedbytakingMR in the formulae following asthebendingmomentatthebaseofthestructurederivedfromtheultimatefactoreddeadload(permanentactions)andwindloads(variableactions).
Note2:Wherecantilevermastsarelocatedwithin4.5metresofthe‘Pointfromwhichset-backismeasured’,asreferredtoinTD19(DMRB2.2.8)orwithinthecentralreserve,thedesignofattachmentsystemsandanchoragesshallbesuchthatremovalandreplacementofdamagedcantilevermastsmaybereadilyachieved.Thisshallbeachievedbyprovidinganinternallythreadedcomponentintheanchoragetoreceivetheholdingdownbolts.
10.3 TypicalarrangementsareshowninFigure5whichapplytobothplatessupportedonbeddingmaterialandplatessupportedonlevellingnutsonly,withouteffectivebedding.
10.4 Whentheweightofthestructureistobecarriedbynutsbeneaththeflangeplate,theholdingdownboltsshallbedesignedtoresistalladditionalstressesarisingfromthisconstructiondetail,andprotectedagainstcorrosion.Whentheweightofthestructureissupporteddirectlythroughtheflangeplatetothesubstructure,thespaceshouldbepackedwithasuitablebeddingmortar.
10.5 Thediameterofcircularflangeplatesshallnotbelessthanthepitchcirclediameteroftheholdingdownboltsplus2.5timesthediameterofthebolts.
10.6 Inthefollowingprocedureitisassumedthatbendingaboutthev-vaxiswillbecritical,whichisthecaseforcolumnsonsquareflangeplateswithfourholdingdownboltsasshowninFigure5.ThemoregeneralcaseiscoveredinAnnexC.
10.7 Theflangeplateshallbecapableofdevelopingamomentofresistanceabouteachaxis,takenattheundersideoftheflangeplate,atleast1.2timesthetheoreticalultimatemomentcapacity,MR(=Mup)oftheactualstructurecalculatedatbaselevelinaccordancewithBSEN40-3-3:Clause5.6.2.
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10.8 Thebendingmomentintheflangeplateshallthusbetakenas:
⎭⎬⎫
⎩⎨⎧
−=4a
20.63D5.0 1.2MM R
( )3
M
y2f
p x10γf
x 4
x t0.63Dc 2M −=
(in N.m)
(in N.m)
(inN.m)
whereD=2RandRisthemeanradiusasdefinedinBSEN40-3-3:Figure3;andaistheboltspacingasshowninFigure5.
10.9 Themaximumbendingintheflangeplate,M,shallnotexceedtheplasticmomentcapacityoftheflangeplate,Mp.Forasquareflangeplatewithacentrallylocatedholenotexceeding0.3Dindiameter(refertoFigure5,detailB),Mp is given by:
⎭⎬⎫
⎩⎨⎧
−=4a
20.63D5.0 1.2MM R
( )3
M
y2f
p x10γf
x 4
x t0.63Dc 2M −=
(in N.m)
(in N.m) (inN.m)
where:
γM=1.15;c=thewidthoftheflangeplate(inmm);tf=thethicknessoftheflangeplate(inmm);
fy=theyieldstressintheflangeplate(inN/mm2);andDisasdefinedin10.8.
Wherethecentrallylocatedholeandthecolumnbasearethesamediameter(refertoFigure5,DetailA),MpshallbecalculatedinaccordancewiththeproceduregiveninAnnexC.
10.10 Shearandbearingshouldnotgovernthedesignoftheflangeplate,providededgedistancesoftheholdingdownboltscomplywiththefollowingrequirements.Theminimumdistancefromthecentreoftheboltholetotheedgeoftheplateshallnotbelessthan1.5dwheredisthediameterofthehole.
Inaddition,forslottedholestheminimumdistancefromtheaxisoftheslottedholetotheadjacentedgeoftheplateshallnotbelessthan1.5dandtheminimumdistancefromthecentreoftheendradiusofaslottedholetotheadjacentedgeoftheplateshallnotbelessthan1.5d.
Design of Welds
10.11 Theconnectionbetweenthecolumnandtheflangeplateshallbecapableofdevelopingthetheoreticalultimatemomentofresistanceoftheactualcolumnandtheequivalentultimateshearforce,bothasderivedin10.7above.
10.12 Weldsshallbedeemedtomeettheserequirementsprovidedthethroatthicknessofthetopweldisnotlessthankxtwhere:k=avaluebetween1.0and1.5dependingonthetypeofwelduse.
Forexample:
k=1.5forthefilletweldsofdetailBinFigure5,andfortheouterfilletweldofdetailAinFigure5,
k=1.0forafullpenetrationbuttweld.
t=thewallthicknessofthecolumnattheflangeplate.
AmoreaccurateprocedureforthedesignofweldsisgiveninAnnexC.
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Design of Holding Down Bolts
10.13 TheholdingdownboltsshallbecapableofdevelopingthetheoreticalultimatemomentcapacityoftheactualcolumnMR(=Mup)calculatedatthebaselevelinaccordancewithBSEN40-3-3:Clause5.6.2andanequivalentultimateshearforce,FR(=2MR).
10.14 Thetensilestress(σ)inholdingdownboltsmaybetakenas:
( )2
et
3R N/mm
A a 210 x M 1.2
=σ
( )2
eqb
R N/mm A nF 1.2
=τ
Mq γ≤
⎪⎭
⎪⎬⎫
⎪⎩
⎪⎨⎧
⎟⎟⎠
⎞⎜⎜⎝
⎛ τ+⎟⎟
⎠
⎞⎜⎜⎝
⎛ σ 1f
2f
2/122
t
where:
Aet=thetensilestressareasinthethreadoftheboltobtainedfromtheappropriatestandard;
a=theboltspacingasshowninFigure5.
10.15 Theshearstress(τ)intheboltsmaybetakenas:
( )2
et
3R N/mm
A a 210 x M 1.2
=σ
( )2
eqb
R N/mm A nF 1.2
=τ
Mq γ≤
⎪⎭
⎪⎬⎫
⎪⎩
⎪⎨⎧
⎟⎟⎠
⎞⎜⎜⎝
⎛ τ+⎟⎟
⎠
⎞⎜⎜⎝
⎛ σ 1f
2f
2/122
t
where:
Aeq=thesectionalareaoftheunthreadedshankoftheboltiftheshearplanepassesthroughtheunthreadedpartbuttakenasAetiftheshearplanepassesthroughthethreadedpart;
nb=totalnumberofboltsfixingtheflangeplate.Whereslottedholesareusednb shall not include bolts in holeswheretheslotalignswiththedirectionoftheappliedshearforce.
10.16 Boltsintensionandshearshallcomplywith:
( )2
et
3R N/mm
A a 210 x M 1.2
=σ
( )2
eqb
R N/mm A nF 1.2
=τ
Mq γ≤
⎪⎭
⎪⎬⎫
⎪⎩
⎪⎨⎧
⎟⎟⎠
⎞⎜⎜⎝
⎛ τ+⎟⎟
⎠
⎞⎜⎜⎝
⎛ σ 1f
2f
2/122
t
where:
γmistakenas1.30;ft is the lesser of:
(i) 0.7xminimumultimatetensilestress;or
(ii) eithertheyieldstressorthestressatpermanentsetof0.2%,asappropriate;
fq=yieldstressofbolts(factoredby0.85inthecaseofblackbolts).
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10.17 Dueconsiderationofthecapacityofthecompleteanchoragetoresisttheforcesinvolved(1.5MR and 1.5FR)shouldalsobemadewithregardtoembedmentandpulloutbasedona90°conerecommendedin“HoldingdownboltdesigntoEurocode2”,ConcreteSociety,2010.
Bearing Stresses Under Flange Plates
10.18 Thebearingstressonthefoundationmediumshouldbederivedonabasiscompatiblewiththeassumedbendingmodev-v,oneitheraplasticorelasticbasisasrequired.Onaplasticbasis,themaximumbearingstressforbendingaboutv-vmaybetakenas:
)/(0.7R)0.5c(aR) - c (0.7 0.7
10 x M 3 22
3R mmN
++
whereMR,c,aandRareallasdefinedabove.
10.19 Thebearingstressesinanybeddingmortarundertheflangeplatesshallnotexceed20N/mm2.ThemaximumbearingstressesontheconcreteunderaflangeplateshallbeinaccordancewiththerequirementsofBSEN1992.
10.20 TherequirementsforfoundationsonmasonryshallbeagreedwiththeOverseeingOrganisation.
10.21 Forbasesfoundedonsteelbridgedecksamorethoroughanalysisisrequiredandisoutsidethescopeofthisstandard.
Design of Anchorages to Bolts
10.22 Thisisdependentonthemediuminwhichtheanchoragesaremade.Theanchoragesshallbedesignedtocaterforamaximumtensileforce,TA,andassociatedshear,FA, as follows:
TA=1.25σAet(inN);and FA=1.25τAeq(inN).
whereσ,τ,AetandAeqareallasderivedabove.
ThecapacityoftheanchorageshallbederivedinaccordancewithSection11(andtherelevantpartsofEN1997).
10.23 Thesupportingstructureshallbedesignedtoresisttheaboveanchorageloadswithoutdamage.Thetensilestrengthoftheconcreteshouldbeignoredinthecalculations.Theconcreteinthefoundationorbridgecomponenttowhichacolumnisfixedshallbereinforcedagainstburstingassociatedwiththeaboveinternalforcesgeneratedbytheholdingdownbolts/anchoragesystem.
Use of Levelling Nuts and Slotted Holes
10.24 Wherelevellingnuts(orothersystemofpermanentpackers)arebeingusedwithouteffectivebeddingitshallbeassumedthatallthebearingstressesaretransferredtothelevellingnuts.Thenutsandwashersonbothsidesoftheflangeplatethusneedtobesufficientlyoversizedtopreventanylocalisedplatefailureduetoconcentrationofstresses.ThismaybeachievedbyusingwasherscomplyingwithBSENISO7093,providedtheholeorwidthoftheslottedholedoesnotexceeddo+4mmwheredo is the diameter of the holdingdownbolts.
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10.25 Forslottedholes,whichprovideflangeplaterotationsofupto±5°asshowninFigure6,washersofadequatethicknessshallbeprovidedonbothsidesoftheflangeplatetotransferloadintotheholdingdownbolts.WasherscomplyingwithBSENISO7093maybeusedprovidedthewidthoftheslottedholesdoesnotexceeddo+6mm.
10.26 Whereholeorslottedclearancesaregreaterthantheabovevalues,considerationshouldbegiventotheuseofspecialplatewashers.Wherelevellingnutsareusedthenutandwashersizeshallbethesameaboveandbelowtheflangeplate.
Figure 5 Typical Arrangement of Flange Plate
Note: 1. DetailsAandBaretypicalonlyandmaybeusedwithcircularoroctagonalcolumnsifrequired.
2. R=meanradiusasdefinedinBSEN40-3-3(Figure3).
3. ‘*’:Radiusofcentrallylocatedholeshallnotexceed0.3R.
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Figure 6 Slotted Holes Arrangement
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Chapter 11Foundations
Volume 2 Section 2Part 1 BD 94/17
11. FOUNDATIONSFoundations – General
11.1 Foundationsshalleitherconsistof:
(i) reinforcedconcrete,designedinaccordancewithparagraphs11.10to11.16asappropriate;or
(ii) plantedcolumnsandposts,designedinaccordancewithparagraphs11.3to11.9asappropriate;
(iii) plantedprefabricatedconcreteormetalcolumnsdesignedinaccordancewith11.3to11.17asappropriate.
Note: Thedesignrulesgiveninparagraphs11.3to11.12donotapplytofoundationsonslopes,wherestabilityofthegroundneedstobetakenintoaccount.Insuchinstances,specialistgeotechnicaladviceshallbesought.GuidancecanbefoundinChapter5oftheInstituteofHighwayEngineersSignStructuresGuide,3rdEdition(2010).
Note: PlantedcolumnsshallnotbeusedforCCTVmasts.
11.2 AlternativeformsoffoundationmaybeusedsubjecttotheapprovaloftheOverseeingOrganisation.
Foundations for Planted Columns, Posts and Prefabricated FoundationsPlanting Depth:
11.3 Whereaminorstructureistobeplanteddirectlyintheground,theplantingdepthshallbeselectedfromTable7ofBSEN40-2relatedtotheoverallheightofthestructure.Inthecaseofprefabricatedfoundationstheplantingdepthandeffectivediametershallbeselectedtoensurecompliancewiththecalculationmethodprovidedbelow.
Note: Fortrafficsign/signalposts,thevaluesappropriatetothecentralcolumnofthistablemaybeused.Wheretheheightislessthan2madepthof600mmmaybeadopted,providedtherequirementsofparagraph11.6aresatisfied.
Tochecktheadequacyoftheselectedplantingdepth,takingaccountofthegroundconditionsatthesite,thecalculationproceduregivenbelowshallbeadopted.
11.4 Thegreatestdestabilisingmoment,MDS,arisingfromapplicationoftheun-factoreddesignloads(e.g.windloadordynamicloadfromsnowclearance)totheminorstructureanditssupportsshouldeitherbecalculatedorobtainedfromthedesigner.Thedestabilisingmomentshallbecalculatedaboutafulcrumpointlocatedat1/√2oftheplantingdepthbelowground.
Thedestabilisingmomentshallbemultipliedbyamodelfactorγs;dof1.25.
11.5 ThegroundresistancemomentMg, should be calculated using the following formula:
10P x DG x M
3
g =
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Where:
G isafactordependentonthegroundinwhichthecolumnisplanted(inkN/m2perm).RefertoTable3fortypicalvaluesofG.
D istheminimumdiameter(orminimumdistanceacrossflatsformulti-sidedsections)ofthetrafficsignintheground(inm).
P istheplantingdepth.
11.6 TheplantingdepthissatisfactoryifMg>γs;dxMDS.
11.7 Ifthiscriterionisnotsatisfiedthentheplantingdepthshallbeincreasedand/ortheeffectivediameteroftheminorstructureshallbeincreased.Thelattercanbeachievedbybackfillingtheexcavationholewithmassconcreteoranacceptablefillmaterial(referto‘Back-filling’below);theeffectivediameterofthetrafficsign/signalpostmaythenbetakenastheminimumdiameteroftheexcavationhole.
Quality of soil G (kN/m2 per m)
Soil Impact Factor
ksi
Good:Compact,well-gradedsandandgravel,hardclay,well-gradedfineandcoarsesand,decomposedgraniterockandsoil. Goodsoilsdrainwell.
630 0.2
Average:Compactfinesand,mediumclay,compactwelldrainedsandyloam,loosecoarsesandandgravels. Averagesoilsdrainsufficientlywellthatwaterdoesnotstandonthesurface.
390 0.3
Poor:Softclay,clayloam,poorlycompactedsand,clayscontainingalargeamountofsiltandvegetablematter,andmade-upground. WheretheQualityisunknown,itshallbetakenasPoor.
230 0.5
WheretheQualityisunknown,itshalltakenasPoor.
Table 3 Ground Factor G and soil impact factor ksi
Back-filling:
11.8 ThecalculationofgroundresistancemomentMg,isbasedontheexcavatedholeintowhichtheminorstructureisplantedbeingback-filledwiththeexcavatedmaterialormaterialofbetterquality.
Thefollowingshallbespecifiedtotheinstaller:
(a) allback-fillingmaterialshallbeplacedin150mmthicklayersandwellcompacted;wherethemanufacturerproposestouseprecastfoundations,thebackfillingmaterialandprocedureshallbedescribed;
(b) duringcompaction,careshallbetakentoensurethatthecorrosionprotectionsystemfortheminorstructure is not damaged;
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(c) wheretheexcavatedholeisback-filledwithconcrete,theconcreteshallextendfromthebaseofthe minor structure to ground level; and
(d) wherepavingorbituminoussurfacingistobeappliedaroundtheminorstructure,thetopleveloftheconcretemaybereducedbythethicknessofthesurfacing.
11.9 Plantedcolumnsshallincorporateamechanismwhichpreventsrotationofthecolumnorpostinthegroundunderwindloadingwheresignificanttorsionalloadingcanarise.Thedesignofplantedcolumnsshalltakeaccountofsettlementanditseffectonclearancesifrelevant.
Foundation for Columns with Flange Plates
11.10 ThedesignprinciplesoffoundationsshallbebasedonthedesignmethodsgiveninBSEN1997-1.ThefoundationshallbedesignedtoresistthefoundationdesignmomentMfd and foundation design shear force Ffdderivedasfollows.
MfdshallbethegreateroftheimpactmomentMiandthemomentobtainedfromBSEN40-3-1,BSEN12899-1orILPPLG07asappropriate,factoredbytheappropriatepartialfactoronload,γF (refertoBSEN1997),forthefailuremodeunderconsideration.
FfdshallbethegreateroftheimpactshearforceFiandthehorizontalforceobtainedfromBSEN40-3-1, BSEN12899-1orILPPLG07asappropriate,factoredbytheappropriatepartialfactoronload,γF (refertoBSEN1997),forthefailuremodeunderconsideration.
Fordestabilizingactions(e.g.overturningmoment)γF;dstshallbetakenasatleast1.5.
Forstabilizingactions(e.g.gravityresistancetooverturning)γG;stbshallbetakenas0.9orless.
MiandFi are derived as follows:
Mi=ksiMR
Fi=ksiFR
wheretheultimatemomentofresistanceoftheactualcolumnatthebaselevel,MR, is calculated in accordancewithBSEN40-3-3:clause5.6.2togetherwithanequivalentultimateshearforce,FR.
Anupperboundtotheequivalentultimateshearforcemaybetakenas:
RefertoBSEN40-3-3forthecalculationofMp.
Thisassumesthatthepointofimpactis0.5mabovethetopofthefoundation.
Thesoilimpactfactor,ksiisgiveninTable3basedonthethreetypesofsoillistedtherein.
Foundations for Cantilever Masts with Flange Plates
11.11 Whencantilevermastsarepositionedinlocationsasgiveninparagraph2.6thefollowingproceduremaybeused.
up
upR 2M
0.5M
F ==
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11.12 Foundationsshallconsistofreinforcedconcreteblocks.ThestructuralconcreteshallbedesignedinaccordancewithBSEN1992.
11.13 ThedesignloadsforthefoundationshallbethenominalloadsandnominalwindloadingappliedbythecantilevermastwhendesignedinaccordancewiththisStandard,factoredbytheappropriatepartialfactorsonload,γF(refertoBSEN1997).
11.14 ThedesignofthefoundationshallbebasedonthedesignmethodsgiveninBSEN1997,usingthepartialfactorsonactionsgivenin11.10above.
11.15 Becauseofthedifferenceinthebehaviourofthecantilevermastanditsfoundation,intheabsenceofmoreaccurate information, the following may be assumed:
Thebasicwindloadtransferredfromthecantilevermasttothesubstructureatthetopofthesubstructurereducesto1/βofthisvalueatthebottomofthesubstructureandfoundation.βisthefactorfordynamicbehaviourgiveninBSEN40-3-1:Clause3.2.4.
11.16 UnlessotherwiseagreedwiththeTechnicalApprovalAuthority,thecriteriagivenin11.10shallapplywhencantilevermastsarepositionedinlocationsotherthanthosegiveninparagraph2.6.
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Chapter 12References
Volume 2 Section 2Part 1 BD 94/17
12. REFERENCES12.1 British Standards Institution
BSEN40:LightingColumns:
Part1:Definitionsandterms
Part2:Generalrequirementsanddimensions
Part3-1:Designandverification–Specificationforcharacteristicloads
Part3-2:Designandverification–Verificationbytesting
Part3-3:Designandverification–Verificationbycalculation
Part4:Requirementsforreinforcedandprestressedconcretelightingcolumns
Part5:Requirementsforsteellightingcolumns
Part6:Requirementsforaluminiumlightingcolumns
Part7:Requirementsforfibrereinforcedpolymercompositelightingcolumns
BSEN1011-1:Welding.Recommendationsforweldingofmetallicmaterials.Generalguidanceforarcwelding
BSEN1011-2:Welding.Recommendationsforweldingofmetallicmaterials.Generalguidanceforarcwelding
BSEN1090-1:Executionofsteelstructuresandaluminiumstructures:Requirementsforconformityassessmentofstructuralcomponents
BSEN1317-2:Roadrestraintsystems.Performanceclasses,impacttestacceptancecriteriaandtestmethodsforsafetybarriersincludingvehicleparapets.
BSEN1991-1-4:Actionsonstructures.Part1.4WindActions
BSEN1992-1:Eurocode2DesignofConcreteStructures
BSEN1993-1-9:Eurocode3:DesignofSteelStructures:Part1.9:Fatigue
BSEN1993-3-1:Eurocode3:DesignofSteelStructures:Part3.1:Towers,mastsandchimneys–Towersandmasts
BSEN1997-1-1:Eurocode7:GeotechnicalDesign.Generalrules
BSEN12767:Passivesafetyofsupportstructuresforroadequipment.Requirements,classificationandtestmethods
BSEN12899-1:Fixed,verticalroadtrafficsigns–Part1:Fixedsigns
BSENISO7093–Plainwashers–Largeseries–ProductgradesAandC
PD6547:GuidanceontheuseofBSEN40-3-1andBSEN40-3-3,BSI
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Chapter 12References
Volume 2 Section 2Part 1 BD 94/17
12.2 Design Manual for Roads and Bridges
Volume1:Section1ApprovalProcedures
Volume1:Section3GeneralDesign
12.3 Manual of Contract Documents for Highway Works. (MCHW)
Volume1:SpecificationforHighwayWorks(MCHW1)
Volume2:NotesforGuidanceontheSpecificationforHighwayWorks(MCHW2)
12.4 Other Publications
HoldingdownboltdesigntoEurocode2–PublishedbyTheConcreteSociety–November2010
TheInstitutionofLightingProfessionals,ProfessionalLightingGuideNumber7,HighMastsforLightingandCCTV,2013Edition,sections1and2(ILPPLG07)
InstituteofHighwayEngineersSignStructuresGuide3rdEdition(2010)
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Volume 2 Section 2Part 1 BD 94/17
13. APPROVALApprovalofthisdocumentforpublicationisgivenby:
DepartmentforInfrastructureClarence Court10-18AdelaideStreetBelfast PBDOHERTY BT28GB DirectorofEngineering
WelshGovernmentTransport SHAGUECardiff DeputyDirectorCF103NQ NetworkManagementDivision
TransportScotland8thFloor,BuchananHouse58PortDundasRoadGlasgow RBRANNENG40HF ChiefExecutive
HighwaysEnglandTempleQuayHouseTheSquareTempleQuayBristol MWILSONBS16HA ChiefHighwayEngineer
AlltechnicalenquiriesorcommentsonthisDocumentshouldbesentto [email protected]
13/2 August 2017
Chapter 13Approval
Volume 2 Section 2Part 1 BD 94/17
August 2017 A/1
Volume 2 Section 2Part 1 BD 94/17
Annex ALimit States for Cantilever Masts
ANNEX A LIMIT STATES FOR CANTILEVER MASTS
Limit State Description
Partial Factor on Load γF
Limit State Type
Dead Load Superimposed Dead Load
Wind Load Buffeting from High Vehicles
Strength(STR) ULS 1.20 1.20 1.20 –
Fatigue SLS 1.00 1.00 1.00 1.00
Deflection SLS 1.00 1.20 1.00 0.50*
Table A1 Limit States and Partial Factors
Element and Position Direction of Deformation LimitingTopofPost HorizontalΔx1 or Δy 1/100ofheightofpost
TipofCantilever HorizontalΔx2 1/100ofoutreachplusheightofpost
TipofCantilever Vertical Δz 1/100ofoutreachplusheightofpost
Table A2 Limiting Structural Deformations of Cantilever Masts [See Figure 1]
*Itshouldbenotedthatthepartialloadfactor,γFL,giveninTableA1is0.5.Thisisbecausethedesignpressuresforbuffetingduetohigh-sidedvehiclesgiveninsectionB.11havebeensettocalculatethetotalstressrangeexperience.Thatis,theresponsefrompeakpositivepressuretopeaknegativepressure.Allthatisrequiredforcalculationofheadroomisthedeflectionduetopeaknegativepressurefromthestaticequilibriumposition.Thisisapproximatelyhalfthepeak-to-peakresponse,hencethepartialloadfactor,γFL,of0.5.
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Annex ALimit States for Cantilever Masts
August 2017 B/1
Volume 2 Section 2Part 1 BD 94/17
Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
ANNEX B FATIGUE CHECKS OF STEEL STRUCTURES AND GUIDANCE FOR WELD CLASSIFICATION
B.1 Whenundertakingfatiguechecksinaccordancewiththefollowingrules,nominalstressesshallbeusedbasedonnominalsectionproperties.Thestressconcentrationsinherentinthemake-upofaweldedjoint(arising,forexample,fromthegeneraljointgeometryandtheweldshape)havebeentakenintoaccountintheclassificationofthedetails.
Whereindicated,however,thenominalstressesshallbemultipliedbystressconcentrationfactors,indicativevaluesofwhichareprovidedintherelevantclause.
B.2 Forreinforcementatdooropeningsthegeometricconstraintssetoutin5.13andB.8shallbemet,andstressrangesarounddooropeningsneednotbecalculated.HoweveriftheseconstraintsarenotmetthentherequirementsofB.3orB.4shallbefollowed,asappropriate.
B.3 Forminorstructuresotherthancantilevermastsfortrafficsignalsand/orspeedcamerasthatprojectoverthecarriageway,onlyfatigueduetowindgustloadingshallbeconsideredandtherequirementsofB5toB10shallbesatisfied.
B.4 Forcantilevermastsfortrafficsignalsand/orspeedcamerasthatprojectoverthecarriagewaythefatigueeffectsfromwindgustloadingandhighvehiclebuffetingshallbecombinedandtherequirementsofB11toB13shallbesatisfied.
Fatigue Due to Gust Wind Loading
B.5 Acheckonfatigueatandadjacenttoeachweldedsection,includingtheendsofreinforcementatdooropeningswhererelevant,shallbeundertakenusingastressrangeσr, given by:
⎟⎟⎠
⎞⎜⎜⎝
⎛⎟⎟⎠
⎞⎜⎜⎝
⎛−=
stat
vssr c
cβ110.25σσ
where:
σs isthestresscalculatedatthispositionforthedesignforcesandmomentsspecifiedinSection4ofBSEN40-3-1;
β isthedynamicresponsefactor(Clause3.2.4ofBSEN40-3-1);
cstat istheaverageshapecoefficientforthetophalfofthecolumnasusedforthestaticanalysisandgiveninFigure3ofBSEN40-3-1;
cvs is1.2forcircularsections;
is1.3foroctagonalsectionswithr/D>0.075;
is1.45foroctagonalsectionswithr/D<0.075;
r is the radius of the corner;
D isthedistanceacrosstheflats.
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
B.6 ThisstressrangeshallbelessthanthatobtainedfromB.7,appropriatetotheclassofdetailbeingconsidered and for a number of cycles n1 given by:
n1=106NfL
where:
Nf isthefrequencyofvibrationofthecolumn(Hz);
L isthedesignlifeofthestructure(years).
B.7 Foradesignlifeof25years,themaximumallowablestressrangeisgiveninFigureB1.1(a)orFigureB1.1(b)appropriatetotheclassofdetailunderconsiderationanddependentonthefrequencyNf(Hz).Thesecurvesarefordesignandincorporateapartialfactoronfatiguestrength.ThemethodofdefiningtheS-NcurvesgiveninFigureB1.1(a)andFigureB1.1(b)isbytwonumbersjoinedbyahyphen.Thefirstnumberisthereferencestrengthat2x106cyclesandthesecondisthemvaluewhichisaconstantapplicabletovaluesofn1upto5x106cycles.ThisistheprocedureadoptedfordefiningfatiguestrengthinBSEN1993-1-9.ThebasisofthecurvesinFiguresB1.1(a)andB1.1(b)isgiveninB.8.
Note: ForadesignlifeofLyearsFigureB1.1maybeusedbyadoptinganeffectivefrequencyNfe as the horizontalscalegivenby:
25L x N N ffe =
B.8 Fatigueiscriticallydependentongeometricalconfigurationsandfabrication.
Thefollowinggeometricandfabricationconstraintsoncrosssectionsofsteellightingcolumnsshallbesatisfied,inordertousetheclassesofdetailsasprovidedinB.9.
Flange Plates
(a) Thecolumn/flangeplateweld1A,2/1and2/2showninFiguresB.2,B.3andB.4shallhaveathroatsizeKtimesgreaterthanthethicknessoftheadjacentshaftmaterial,whereKisgivenby:
Weld K
1A 1.10
2/1 1.25
2/2 1.25*
*Orusefullpenetrationbuttweld
(b) Thethicknessofthebasematerialtbshallbenotlessthanthethicknessoftheadjacentshaftmaterial,ts.
Shoulder Joints
(c) WeldedShoulderjointsasshowninFiguresB.5,B.6andB.7shallhaveanangleofinclinationtotheaxisofthecolumns,α,betweenthefollowinglimits:
12°<α<35°
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
(d) TheshoulderjointweldAasshowninfiguresB5,B6andB7shallhaveathroatsize10%greaterthanthethicknessoftheadjacentshaftmaterial,ts.
(e) Toensurethatwelddetail6(seeFigureB.8)behavesasintendedthelappedlengthshallbeatleast1.5timesthediameterofthelappedshaft.Eachsectionshallbegalvanisedtoavoidtheriskofprematurefailureduetorusting.
Door Openings
(f) StiffenedandunstiffeneddooropeningsshallcomplywiththeconstraintsshowninFigureB.9.Inadditionthe following fabrication constraints shall be met:
i. sharpirregularitiesatfreeedgesduetotheflamecuttingprocessshallbegroundout;
ii. noweldingshallbecloserthan10mmfromtheedgeofthedoorunstiffenedopening.
Longitudinaledgestiffenersshallbecontinuousovertheirfullextent.
B.9 Guidanceonclassesoftypicalwelddetailsincorporatingstressconcentrationfactors,Kf,whichcomplywiththeconstraintsofB.6aregiveninFiguresB.2toB.9forweldsmadeusingnormalcommercialpractice,e.g.manualweldswithoutNDTorothertesting.ThisguidancewasbasedonfatiguetestsofarepresentativenumberofdetailsprovidedbyarangeofUKlightingcolumnmanufacturers.Howeverclassificationiscriticallydependentonweldingqualityandfabricationmethods,andhencetheinformationprovidedisforguidanceonly.Closercontroloftheweldingandfabricationprocessand/orpost-weldtreatmentmayimprovetheweldclassification.ForotherweldeddetailsspecialistadviceshouldbesoughtandreferencemadetoBSEN1993-1-9.
B.10 FiguresB1.1(a)and(b),thefatiguelifecurves,arebasedon:
(a) No.ofcyclestofailureN=2x106
where σo =detailscategory(50,…120…)
m =slopeofcurve(3forFigureB1.1(a)and4forFigureB1.1(b))
σR =stressrange
(b) ThenumberofcyclesrelatetothefrequencybytheequationinB.4:
N=106NfL
(c) ThusforadesignlifeofLof25years:
N=25x106Nf
m
⎟⎟⎠
⎞⎜⎜⎝
⎛
r
o
σσ
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
(d) Thus,therelationshipbetweenσRandNf(theplotsofFiguresB1.1(a)andB1.1(b))is:
i.e.
e.g.forclassdetail120:4
σo=120
m=4
σR 100 90 80 70 60 50
Nf 0.166 0.253 0.405 0.691 1.280 2.650
Fatigue from High Vehicle Buffeting
B.11 Thestressrangeσr2iinanypartofthestructureforfatigueduetohighvehiclebuffetingshallbecalculatedbyapplying:
(i) apressureofPdtotheportionofthecantileverarmandanyattachmentsabovethecarriagewayvertically downwards; and
(ii) apressureofPdtotheportionofthecantileverarmandanyattachmentsabovethecarriagewayhorizontallyagainstthedirectionofthetraffic.
ThepressurePd shall be calculated as:
Pd=600h-0.25–400(inN/m2)
Wherehiseither:
(i) Thedistancefromthetopofthehighsidedvehicletotheundersideofanyhorizontalsurface;or
(ii) Thedistancefromthetopofthehighsidedvehicletothecentreofpressureofanyverticalsurface.
Atypicalhighsidedvehicleheightof4.2metresshallbeused.(seenote3,clauseB.12).TheformulaforPdappliesforavalueofuptoh=5m.
Appliedloadsshallbecalculatedastheproductoftheappropriatepressureandprojectedarea.PartialloadfactorγfLshallbetakenas1.0.
f6
m
R
o6 N 10 x 25σσ
10 x 2 =⎟⎟⎠
⎞⎜⎜⎝
⎛
m
Rσoσ
1008Nf ⎟
⎟
⎠
⎞
⎜⎜
⎝
⎛=
4
Rf σ
120100
8N ⎟⎟⎠
⎞⎜⎜⎝
⎛=
f6
m
R
o6 N 10 x 25σσ
10 x 2 =⎟⎟⎠
⎞⎜⎜⎝
⎛
m
Rσoσ
1008Nf ⎟
⎟
⎠
⎞
⎜⎜
⎝
⎛=
4
Rf σ
120100
8N ⎟⎟⎠
⎞⎜⎜⎝
⎛=
f6
m
R
o6 N 10 x 25σσ
10 x 2 =⎟⎟⎠
⎞⎜⎜⎝
⎛
m
Rσoσ
1008Nf ⎟
⎟
⎠
⎞
⎜⎜
⎝
⎛=
4
Rf σ
120100
8N ⎟⎟⎠
⎞⎜⎜⎝
⎛=
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Fatigue Damage Assessment
B.12 Fatiguedamageshallbeassessedasfollows:
(i) Forfatigueduetogustwindloading
The number of cycles, n1,shallbecalculatedfromB.6
Thecorrespondingnumberofcyclestofailure,N1 shall be given by:
m
r1
o61 σ
σ10 x 2N ⎟⎟
⎠
⎞⎜⎜⎝
⎛=
m
r2i
o62i σ
σ10 x 2N ⎟⎟
⎠
⎞⎜⎜⎝
⎛=
(ii) Forfatigueduetohighvehiclebuffeting:
The number of cycles for each lane in a carriageway, n2i, shall be given by:
n2i=1.6x107.L.Fi
Thecorrespondingnumberofcyclestofailure,N2i, is given by:
m
r1
o61 σ
σ10 x 2N ⎟⎟
⎠
⎞⎜⎜⎝
⎛=
m
r2i
o62i σ
σ10 x 2N ⎟⎟
⎠
⎞⎜⎜⎝
⎛=
Where:
L isthedesignlifeofthestructure(years)
σo isthedetailscategory(50,…120…), (seeparagraph5.15and,forrelevantdetails,fromB.8);
Fi isthelaneallocationfactor(seeTableB1);and
m istheslopeofcurve(seeparagraphB.7).
Type of carriageway
Lane Allocation Factors, Fi
Lane 1 Lane 2 Lane 3 Lane 4D2M 0.7 0.3 – –
D3M 0.6 0.4 0.0 –
D4M 0.4 0.4 0.2 0.0
Table B1 Lane Allocation Factors
(iii) Thefatigueeffectsfromwindgustloadingandhighvehiclebuffetingshallbecombinedandshallsatisfy the following criterion:
1
2
2
1
1 ≤+∑T
i i
i
Nn
Nn
whereTisthenumberoflanesdirectlybeneaththecantileverarm.
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Notes:
The number of cycles for high vehicle buffeting is based on:
1. Thepassageof7,000suchvehiclesperdayoneachcarriageway.Whereflowsarelessthanthisaverage, then the values of n2ishouldbereducedinproportion.Flowsofhighsidedvehiclesshallbedeterminedbytrafficsurvey.Thetotalnumberofhighsidedvehiclesshallnotbereducedbelowavalueof1,000fordesignpurposes.
2. Atotallogarithmicdecrementofdampingof0.03;wheredampingislessthanthisvaluethenspecialistadviceshouldbesought.
Furthermore:
1. Ahighsidedvehicleheightof4.2metreshasbeenadoptedforcalculatingthepressurePd, as a representativeheightofsuchvehiclescurrentlyinuseonUKhighways;whereaparticularsitehasasignificantlyhigheraveragevehicleheightthenthisshouldbeusedinstead.
2. Thedesignpressure,Pd,assumesthatthemaximumspeedofthehighsidedvehicleislimitedto60mph.Whereregulationspermithighermaximumspeedsthenspecialistadviceshouldbesought.
B.13 Checksonfatigueshallbeundertakenatthefollowingpositions:
(i) atandadjacenttoeachweldedsection;and
(ii) theendofthereinforcementatdooropenings.
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Note:ForbasisofcurvesseeB.9
Figure B1.1(a) Fatigue of Column Stress Range Limit for Class of Weld Detail Based on a 25 Year Design Life Requirement (m=3)
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Note:ForbasisofcurvesseeB.9
Figure B1.1(b) Fatigue of Column Stress Range Limit for Class of Weld Detail Based on a 25 Year Design Life Requirement (m=4)
August 2017 B/9
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld Section to be checked Class of Parent Metal Kf = Kt Kb Kh
1A 1B A-A 30Kf-4(1)
(1) Providedweld1Aisdesignedfortransferofthetotalloadandweld1Bisforsealingonly.Otherwiseadetailedstressanalysisshallbeundertakenandtheresultingstressconcentrationfactorsused.
(2) NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparentmetalshallstillbechecked.
Figure B.2 Weld Detail Type 1
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld Section to be checked Class of Parent Metal Kf = Kt Kb Kh
2/1 A-A 30Kf-4
Note:NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparentmetalshallstillbechecked.
Figure B.3 Weld Detail Type 2/1
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Volume 2 Section 2Part 1 BD 94/17
Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld Section to be checked Class of Parent Metal Kf = Kt Kb Kh
2/2 A-A 30Kf-4
Note:NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparentmetalshallstillbechecked.
Figure B.4 Weld Detail Type 2/2
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Volume 2 Section 2Part 1 BD 94/17
Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld Section to be checkedClass
Parent Metal Weld Throat
3A A-A 90–4 (1) See (2)
3B NochecknecessaryifcriteriaofB/8aremet90–4 (1) See (2)
3C C-C
(1) Incorporatesstressconcentrationfactor,takeKf=1.0. (2) NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparent metalshallstillbechecked.
Figure B.5 Weld Detail Type 3
Note:Jointdetailnotrecommendedforotherthanlightlyloadedshortcolumns
Weld Section to be checkedClass
Parent Metal Weld Throat4 A/A 71–4 (1) See (2)
(1) Incorporatesstressconcentrationfactor,takeKf=1.0. (2) NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparent metalshallstillbechecked.
Figure B.6 Weld Detail Type 4
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Volume 2 Section 2Part 1 BD 94/17
Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld Section to be checkedClass
Parent Metal Weld Throat
5A A/A 90–4 (1) See (2)
5B NochecknecessaryifcriteriaofB/8aremet 120–4 See (2)
5CC-C.Plugsnotgroundsmooth 90–4 –
C-C.Plugsgroundsmooth 120–4 –
(1) Incorporatesstressconcentrationfactor.TakeKf=1.0. (2) NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparent metalshallstillbechecked.
Figure B.7 Weld Detail Type 5
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld Section to be checkedClass
Upper Tube Parent Metal
Lower Tube Parent Metal Weld Throat
6 A/A N/A (1) 71–4 See (2)
(1) Assumestightfitbetweentubesforloadtransferbyshear. (2) Nofatiguecheckneedbeundertakenontheweldthroat.Theparentmetalshallstillbechecked. (3) RefertoB.8(e)regardingthedetailingofthisjoint.
Figure B.8 Weld Detail Type 6
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
Weld/Detail Section to be checked Class
7 Intermediate weld 80–3
8 Intermediate weld 71–3
9 Endweld 50–3
10 Flamecutedge 112–4
(1) Nofatiguestresscalculationsneedbeundertakenprovidedthegeometricandfabricationconstraintsof B.8havebeenmet.Otherwisetheaboveclassificationshouldbeadoptedinconjunctionwithadetailed stressanalysisincorporatingappropriatestressconcentrationfactors.
Figure B.9 Weld Detail Type 7 to 10
Welded stiffener adjacent to openingparallel to column
Welded stiffener adjacent to openingtransverse to column
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Annex BFatigue Checks of Steel Structures and Guidance for Weld Classification
August 2017 C/1
ANNEX C DETAILED DESIGN OF FLANGE PLATESC.1 General
C.1.1 TheproceduregiveninChapter10forthedesignofflangeplatesassumescircularoroctagonalcolumnsconnectedtosquareflangeplateswithacentrallylocatedholenotexceeding0.30Dindiameterandsupportedbyfourholdingdownboltssymmetricallydisposed.Thefollowinggeneralproceduremaybeusedforsquareplateswithcentrallylocatedholeseithernotexceeding0.30Dindiameter,orofdiameterequaltothatofthecolumn(seeFigureC.1).Thisprocedureprovidesdesigncriteriaforthewelds,theplate,theholdingdownboltsandthebearingstresses.
C.1.2 Inadditionaconservativeassumptionhasbeenmadeforthepositionoftheaxisofbending.Theproceduregivenhereinprovidesamoreaccuratederivationofthemaximumbendingmomentontheplatetobeusedindesign.
C.1.3 ForflangeplatesnotcomplyingwiththeconstraintsofC.1.1othersuitabledesignmethods,orfullscaleloadtestsmaybeadopted,subjecttotheapprovaloftheOverseeingOrganisation.
C.2 Derivation of Weld Stresses
C.2.1 Theconnectionbetweenthecolumnandflangeplateshallbecapableofdevelopingtheultimatemomentofresistance,MR,asderivedfromBSEN40-3-3andtheequivalentshearforce,FR.Theconnectionmaybe achieved by welds of leg length, twasshowninFigure5,detailAorB.
Note: InthecaseofdetailBinparticular,thelengthoffilletweld,tw,requiredmayneedtobeconsiderablyinexcessofthewallthickness,t,inordertosatisfytheserequirements.Alternatively,afullpenetrationbuttweldmaybeusedwhichwillautomaticallysatisfytheserequirements.
C.2.2 ThestressinthefilletweldsduetomomentofresistanceMRmaybetakenas:
TheshearstressinthefilletweldsduetotheequivalentshearforceFRmaybetakenas:
τRtheresultantweldstressshallbetakenas:
where R=meanradiusofcrosssection(inmm); tw=filletweldleglength(inmm).
C.3 Capacity of Welds
C.3.1 Thestressinthefilletwelds,τR,shallnotexceedtheweldcapacityτD given by:
( )( )2
w2
3R
1 N/mmin t0.7πR
10Mτ
⋅=
( ) ( ) ( )2
w
R
w
R2 N/mmin
0.7tπRM
0.7tR2πF
τ ==
( ) ( ) )(N/mm 1R
10000.7tπR
Mτττ 22
w
R1/222
21R +⎟
⎠⎞
⎜⎝⎛=+=
( )( )2
w2
3R
1 N/mmin t0.7πR
10Mτ
⋅=
( ) ( ) ( )2
w
R
w
R2 N/mmin
0.7tπRM
0.7tR2πF
τ ==
( ) ( ) )(N/mm 1R
10000.7tπR
Mτττ 22
w
R1/222
21R +⎟
⎠⎞
⎜⎝⎛=+=
( )( )2
w2
3R
1 N/mmin t0.7πR
10Mτ
⋅=
( ) ( ) ( )2
w
R
w
R2 N/mmin
0.7tπRM
0.7tR2πF
τ ==
( ) ( ) )(N/mm 1R
10000.7tπR
Mτττ 22
w
R1/222
21R +⎟
⎠⎞
⎜⎝⎛=+=
( ) ( )2
m
yD N/mmin
32γ455fk
τ+
=
( )inN.ma
2Rα1M 0.6M Ruu ⎥⎦⎤
⎢⎣⎡ −=−
( )inN.m2a
2Rα1M 0.6M Rvv ⎥⎦
⎤⎢⎣
⎡−=−
Annex CDetailed Design of Flange Plates
Volume 2 Section 2Part 1 BD 94/17
C/2 August 2017
where fy istheyieldstressofthecolumnsection(fs)ortheflangeplate(ff)whicheveristhelesser;
γm istakenas1.20;
k =0.9forsidefilletswheretheweldissubjecttolongitudinalshear; or1.4forendfilletsinendconnectionswheretheweldissubjecttotransverseshear; or1.0forallotherwelds.
(Whereinnerfilletsandouterfilletsareusedtogetherkmaybeaggregated,e.g.k=2.8fordetailAinFigure5sincebothareeffectivelyendfilletsforanendconnection.)
C.4 Design of Flange Plates
C.4.1 Derivation of Bending Moments in Flange Plates
C.4.1.1Theflangeplateshallbedesignedtoresistatleasttheeffectof1.2MRatthebaseofthecolumnwhereMR isasderivedfromBSEN40-3-3,andshallbecheckedaboutbendingparalleltooneside(axisu-u)andonthediagonal(axisv-v)seeFigureC.1.
C.4.1.2Themaximumbendingmomentontheflangeplateaxesu-uandv-vforplateswitheffectivebeddingorsupportedonlevellingnutsonlymaybetakenas:
where R=meanradiusofthecolumncrosssection(inmm); a=spacingofthebolts(inmm);
andαrelatestothepositionconsideredformaximumbendingintheplate.Inlieuofmorethoroughanalysisαmaybebasedonthecentroidoftheweldsonthetensileside,i.e.αmaybetakenas0.63.
C.4.2 Bending Capacity of Flange Plate
C.4.2.1Themaximummomentintheflangeplate,M,shallnotexceedtheplasticmomentcapacityoftheflangeplate,Mp.Forasquareflangeplatewherethecentrallylocatedholeisthesamediameterasthecolumnbase(refertoFigureC.1,detailA)Mp is given by:
and
where γm istakenas1.15; c =thewidthoftheflangeplate(inmm); tf =thethicknessoftheflangeplate(inmm); ff =theyieldstressoftheflangeplate(inN/mm2).
( ) ( )2
m
yD N/mmin
32γ455fk
τ+
=
( )inN.ma
2Rα1M 0.6M Ruu ⎥⎦⎤
⎢⎣⎡ −=−
( )inN.m2a
2Rα1M 0.6M Rvv ⎥⎦
⎤⎢⎣
⎡−=−
( ) ( )2
m
yD N/mmin
32γ455fk
τ+
=
( )inN.ma
2Rα1M 0.6M Ruu ⎥⎦⎤
⎢⎣⎡ −=−
( )inN.m2a
2Rα1M 0.6M Rvv ⎥⎦
⎤⎢⎣
⎡−=−
( ) ( ) axis;u -ufor N.min 10γ
f4t
α12RcM3
m
f2f2
p −−=
( ) ( ) axis; v-for v N.min 10γ
f4t
)-1(2R2cM3
m
f2f2
p α+α−=
( ) ( ) axis;u -ufor N.min 10γ
f4t
α12RcM3
m
f2f2
p −−=
( ) ( ) axis; v-for v N.min 10γ
f4t
)-1(2R2cM3
m
f2f2
p α+α−=
Volume 2 Section 2Part 1 BD 94/17
Annex CDetailed Design of Flange Plates
August 2017 C/3
C.5 Design of Holding Down Bolts
C.5.1 Derivation of Stresses in Bolts
C.5.1.1Thetensilestressintheholdingdownboltsmaybetakenas:
where ntisrelatedtothenumberofboltsresistingtensionandtheassumedaxisofbendingandmaybetakenas:
0.5nbforbendingaboutaxisu-u;seeFigureC.1;or 0.25nbforbendingaboutaxisv-v;seeFigureC.1;
Aet =thetensilestressareainthethreadoftheboltobtainedfromtheappropriatestandard; a =theboltspacing; nb =totalnumberofboltsfixingtheflangeplate.
Note: Ingeneral(ntxa)shouldnotbetakenasgreaterthan(a+αR+0.5c)foraxisu-u,norgreaterthan 0.7(a+0.7αR+0.5c)foraxisv-vtoensurecompatibilitywiththeassumedmodeofbendingin5above.
Theshearstressintheboltsmaybetakentobethatderivedin10.14,combinedshearandtensionin10.15andcapacityoftheanchoragefrom10.16.
C.6 Check on Bearing Stress Below the Flange Plate
C.6.1 Thebearingstressgivenin10.17assumesbendingaboutthev-vaxis.Ingeneralitwillbenecessarytoderivethebearingstressonthefoundationmediumforboththeassumedbendingmodesu-uandvv,oneitheraplasticorelasticbasisasrequired.Themaximumcalculatedbearingstressshallnotexceedthevaluedeterminedinaccordancewith10.18.
C.6.2 Onaplasticbasis,themaximumbearingstressforbendingaboutu-umaybetakenas:
C.6.3 Onaplasticbasis,themaximumbearingstressforbendingaboutv-vmaybetakenas:
whereMR,c,a,RandαareallasdefinedinC.4.1above.
)(N/mmA a n10x1.2M
σ 2
ett
3R=
)(N/mmc) 0.5 R α 0.5 a R)(0.75 α - c c(0.5
10xM 3 23
R
++
)(N/mmR) α 0.7 0.5c (aR) α - c 0.7(0.7
10xM 3 22
3R
++
Annex CDetailed Design of Flange Plates
Volume 2 Section 2Part 1 BD 94/17
C/4 August 2017
Figure C.1 Typical Arrangement of Flange Plate
Note: 1. DetailsAandBaretypicalonlyandmaybeusedwithcircularoroctagonalcolumnsifrequired. 2. R=meanradiusasdefinedinBSEN40-3-3(Figure3). 3. ‘*’:Radiusofcentrallylocatedholeshallnotexceed0.3R.
Volume 2 Section 2Part 1 BD 94/17
Annex CDetailed Design of Flange Plates
August 2017 D/1
ANNEX D DETERMINATION OF SHAPE COEFFICIENTS BY TESTING
D.1 Shape Coefficients for Columns
General
D.1.1 ProperlyconductedwindtunneltestsoncolumnsandbracketsshallonlybeundertakenwhenshapecoefficientsarenotavailablefromBSEN40-3-1orfromrecognisedInternationalStandards.AdoptionofvaluesfromthesestandardsorfromwindtunneltestsshallbeagreedwiththeTechnicalApprovalAuthority.Particularcareshouldbetakentoensurethatthevaluesofshapecoefficientsrelatetocross-sectionsofmembersofinfinitelength.
D.1.2 Windtunnelteststoestablishshapecoefficientsshouldbecarriedoutusingfullscalespecimenswhichaccuratelyrepresentthefinalproposedcolumn.Theforcesonthespecimenshallbemeasuredinthedirectionoftheairflowandthedirectionnormaltotheairflow.
D.1.3 Previouswindtunneltestshaveindicatedthatsmallangularrotationsofspecimenscancauseconsiderabledifferencesinshapecoefficients.Thespecimensshallthereforebeturnedinthewindtunnelandmeasurementstakenatangularincrements.Intheregionofeachshapecoefficientthemeasurementsshallbereducedtoapproximately1°ofrotation.ComparisonsshallbemadewiththevaluesofsimilarsectionsgiveninrecognizedInternationalStandardsaspartoftheadoptionandagreementprocedurewiththeTechnicalApprovalAuthoritysetoutin4.
D.2 Shape Coefficients for Lanterns, Cameras, Signs and Brackets
D.2.1 Theshapeandliftcoefficientsforlanterns,camerasandsignsmaybedeterminedfromwindtunneltestsasrequiredbyBSEN40-3-1.Thesetestsshallbecarriedoutonafullscaleshapeoftheelementinatunnelsufficientlylargetoreducesideeffectstoaninsignificantlevel.Thesurfaceconditionofthespecimenshallaccuratelyrepresentthatoftheproductionversion.Whereoptionalattachmentswillbemadetotheelement,eg.photo-electriccontrolunits,gearcomponentextensionsetc,theseshallbeincludedinthetestspecimen.
D.2.2 Whencarryingoutwindtunneltest,forcesbothinthedirectionoftheairflowandinthedirectionnormaltotheairflowshallbemeasured,asshapeandliftcoefficientsarerequiredforallthedirectionsrequiredinD.2.3.Allshapecoefficientsshallbebasedontheprojectedareaoftheelementnormaltotheairflow.
D.2.3 Forcesonanelementshallbemeasuredatincrementsofrotationofapproximately1°betweenthelimitof±10°tothehorizontal.BSEN40-3-1requiresthemaximumvaluebetween±5°tothehorizontalbutamoreconservativevalueshallbeadoptedwherelargeincreasesofcoefficientsareobtainedbetween5°and10°tothehorizontal.Duringtestingtheeffectsofsmallplanrotationsaboutthepointoffixingshallalsobetakenintoaccount.Whereanincreaseinshapecoefficientobtainedwitharotationwithinthelimitsof ±10°thenthisvalueshallbeadopted.
Annex D Determination of Shape Coefficients by Testing
Volume 2 Section 2Part 1 BD 94/17
D/2 August 2017
Volume 2 Section 2Part 1 BD 94/17
Annex D Determination of Shape Coefficients by Testing