VOLUME 2 HIGHWAY STRUCTURES: DESIGN (SUB · PDF fileaugust 2017 design manual for roads and...

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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.

INSTRUCTIONS FOR USE

1. RemoveBD94/07fromVolume2,Section2,Part1.

2. InsertBD94/17intoVolume2,Section2,Part1.

3. Pleasearchivethissheetasappropriate.

Note:AquarterlyindexwithafullsetofVolumeContentsPagesisavailableseparatelyfromTheStationeryOfficeLtd.

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

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

REGISTRATION OF AMENDMENTS

August 2017

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

August 2017 1/1

Chapter 1Introduction

Volume 2 Section 2Part 1 BD 94/17

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.

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.

August 2017 1/3

Implementation

1.4 ThisStandardshouldbeusedforthwithonallschemesfortheconstructionandimprovementoftrunkroads,includingmotorways,currentlybeingprepared,providedthat,intheopinionoftheOverseeingOrganisation,thiswouldnotresultinsignificantadditionalexpenseordelayprogress.DesignOrganisationsshouldconfirmitsapplicationtoparticularschemeswiththeOverseeingOrganisation.WheretheOverseeingOrganisation’scontractdocumentsarebasedontheSpecificationforHighwayWorks(MCHW1)useofthisStandardismandatory.InNorthernIrelandthisstandardshouldbeusedonallroads.WherethisStandardduplicatesorcoversrequirementsinexistingstandardsduringaperiodofco-existence,itshalltakeprecedenceunlessotherwiseagreedwiththeOverseeingOrganisation.

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August 2017 2/1

Chapter 2General Principles

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

2/2 August 2017

Chapter 2General Principles

(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

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)

3/4 August 2017

August 2017 4/1

Chapter 4Use of British Standards and Standards Issued by the Overseeing Organisations

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 4Use of British Standards and Standards Issued by the Overseeing Organisations

August 2017 5/1

Chapter 5Design

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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Chapter 5Design

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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Chapter 5Design

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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Chapter 5Design

5.15 Inordertoundertakeafatiguecheckitisnecessarytodeterminealoadingspectrafromwinddataappropriatetothesite.Intheabsenceofsuchdata,thefatigueloadingprovisionsgiveninAnnexBmaybeadopted.

5.16 Classificationmaybederivedbyfatiguetestingofasampleoftypicalfull-scaledetailsinanindependenttestinglaboratoryandcoveringanappropriatestressrangetoenableafatiguelifecurvetobederived.Sufficienttestsshouldbeundertakentoprovideadesigncurverepresentingmeanminus2standarddeviations.

5.17 Intheabsenceofdataonfatiguelifecurvesandloadingspectra,theproceduresetoutinAnnexBshallbefollowed.

Determination of Shape Coefficients

5.18 Wherewindtunneltestsarenecessaryforthedeterminationofshapecoefficientsforcolumns,bracketsandlanterns,thetestingshallbecarriedoutinaccordancewithAnnexDofthisStandard.

August 2017 5/5

Chapter 5Design

Figure 2 Door Openings

radius r ≥ 20mm

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Chapter 5Design

Figure 3 Typical Shoulder Joint

August 2017 6/1

Chapter 6Fibre Reinforced Polymer Composite Lighting Columns

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.

6/2 August 2017

Chapter 6Fibre Reinforced Polymer Composite Lighting Columns

August 2017 7/1

Chapter 7Door Openings

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

7/2 August 2017

Chapter 7Door Openings

August 2017 8/1

Chapter 8Wall Mounted Brackets

8. WALL MOUNTED BRACKETS8.1 Wallmountedbracketsshallbedesigned,inaccordancewiththerelevantrequirementsforcolumn

brackets.Thebracketshallbefixedtoitssupportbymeansofaflangeplateandanchoragewhichshallbedesignedinaccordancewithparagraph10.9.

8.2 Thewallonwhichthewallmountedbracketsarefixedshallbecapableofcarryingtheadditionalloadsandotherforcesthatmaybetransmittedbythebracket.Thedesignerofthebracketshallprovidethenecessaryloadsforotherstoassesstheadequacyofthewall.

8/2 August 2017

Chapter 8Wall Mounted Brackets

August 2017 9/1

Chapter 9Attachments

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.

9/2 August 2017

Chapter 9Attachments

August 2017 10/1

Chapter 10Flange Plate Connection Between Steel Structure and Foundation

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.

10/2 August 2017

10.8 Thebendingmomentintheflangeplateshallthusbetakenas:

⎭⎬⎫

⎩⎨⎧

−=4a

20.63D5.0 1.2MM R

p x10γf

x t0.63Dc 2M −=

(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

p x10γf

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.

August 2017 10/3

Design of Holding Down Bolts

10.13 TheholdingdownboltsshallbecapableofdevelopingthetheoreticalultimatemomentcapacityoftheactualcolumnMR(=Mup)calculatedatthebaselevelinaccordancewithBSEN40-3-3:Clause5.6.2andanequivalentultimateshearforce,FR(=2MR).

10.14 Thetensilestress(σ)inholdingdownboltsmaybetakenas:

3R N/mm

A a 210 x M 1.2

R N/mm A nF 1.2

Mq γ≤

⎪⎭

⎪⎬⎫

⎪⎩

⎪⎨⎧

⎟⎟⎠

⎞⎜⎜⎝

⎛ τ+⎟⎟

⎞⎜⎜⎝

⎛ σ 1f

where:

Aet=thetensilestressareasinthethreadoftheboltobtainedfromtheappropriatestandard;

a=theboltspacingasshowninFigure5.

10.15 Theshearstress(τ)intheboltsmaybetakenas:

3R N/mm

A a 210 x M 1.2

R N/mm A nF 1.2

Mq γ≤

⎪⎭

⎪⎬⎫

⎪⎩

⎪⎨⎧

⎟⎟⎠

⎞⎜⎜⎝

⎛ τ+⎟⎟

⎞⎜⎜⎝

⎛ σ 1f

where:

Aeq=thesectionalareaoftheunthreadedshankoftheboltiftheshearplanepassesthroughtheunthreadedpartbuttakenasAetiftheshearplanepassesthroughthethreadedpart;

nb=totalnumberofboltsfixingtheflangeplate.Whereslottedholesareusednb shall not include bolts in holeswheretheslotalignswiththedirectionoftheappliedshearforce.

10.16 Boltsintensionandshearshallcomplywith:

3R N/mm

A a 210 x M 1.2

R N/mm A nF 1.2

Mq γ≤

⎪⎭

⎪⎬⎫

⎪⎩

⎪⎨⎧

⎟⎟⎠

⎞⎜⎜⎝

⎛ τ+⎟⎟

⎞⎜⎜⎝

⎛ σ 1f

where:

γmistakenas1.30;ft is the lesser of:

(i) 0.7xminimumultimatetensilestress;or

(ii) eithertheyieldstressorthestressatpermanentsetof0.2%,asappropriate;

fq=yieldstressofbolts(factoredby0.85inthecaseofblackbolts).

10/4 August 2017

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.

August 2017 10/5

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.

10/6 August 2017

Figure 6 Slotted Holes Arrangement

August 2017 11/1

Chapter 11Foundations

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

11/2 August 2017

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

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;

August 2017 11/3

Annex 11Foundations

(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.

upR 2M

11/4 August 2017

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.

August 2017 12/1

Chapter 12References

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

12/2 August 2017

Chapter 12References

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)

August 2017 13/1

Chapter 13Approval

13. APPROVALApprovalofthisdocumentforpublicationisgivenby:

DepartmentforInfrastructureClarence Court10-18AdelaideStreetBelfast PBDOHERTY BT28GB DirectorofEngineering

WelshGovernmentTransport SHAGUECardiff DeputyDirectorCF103NQ NetworkManagementDivision

TransportScotland8thFloor,BuchananHouse58PortDundasRoadGlasgow RBRANNENG40HF ChiefExecutive

HighwaysEnglandTempleQuayHouseTheSquareTempleQuayBristol MWILSONBS16HA ChiefHighwayEngineer

AlltechnicalenquiriesorcommentsonthisDocumentshouldbesentto DMRB_Enquiries@highwaysengland.co.uk

13/2 August 2017

Chapter 13Approval

August 2017 A/1

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.

A/2 August 2017

Annex ALimit States for Cantilever Masts

August 2017 B/1

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:

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛−=

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.

B/2 August 2017

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°

August 2017 B/3

(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

⎟⎟⎠

⎞⎜⎜⎝

B/4 August 2017

(d) Thus,therelationshipbetweenσRandNf(theplotsofFiguresB1.1(a)andB1.1(b))is:

e.g.forclassdetail120:4

σo=120

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.

o6 N 10 x 25σσ

10 x 2 =⎟⎟⎠

⎞⎜⎜⎝

Rσoσ

1008Nf ⎟

⎜⎜

120100

8N ⎟⎟⎠

⎞⎜⎜⎝

o6 N 10 x 25σσ

10 x 2 =⎟⎟⎠

⎞⎜⎜⎝

Rσoσ

1008Nf ⎟

⎜⎜

120100

8N ⎟⎟⎠

⎞⎜⎜⎝

o6 N 10 x 25σσ

10 x 2 =⎟⎟⎠

⎞⎜⎜⎝

Rσoσ

1008Nf ⎟

⎜⎜

120100

8N ⎟⎟⎠

⎞⎜⎜⎝

August 2017 B/5

Fatigue Damage Assessment

B.12 Fatiguedamageshallbeassessedasfollows:

(i) Forfatigueduetogustwindloading

The number of cycles, n1,shallbecalculatedfromB.6

Thecorrespondingnumberofcyclestofailure,N1 shall be given by:

o61 σ

σ10 x 2N ⎟⎟

⎞⎜⎜⎝

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:

o61 σ

σ10 x 2N ⎟⎟

⎞⎜⎜⎝

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 ≤+∑T

whereTisthenumberoflanesdirectlybeneaththecantileverarm.

B/6 August 2017

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.

August 2017 B/7

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)

B/8 August 2017

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

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

B/10 August 2017

2/1 A-A 30Kf-4

Note:NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparentmetalshallstillbechecked.

Figure B.3 Weld Detail Type 2/1

August 2017 B/11

2/2 A-A 30Kf-4

Note:NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparentmetalshallstillbechecked.

Figure B.4 Weld Detail Type 2/2

B/12 August 2017

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.

Note:Jointdetailnotrecommendedforotherthanlightlyloadedshortcolumns

Parent Metal Weld Throat4 A/A 71–4 (1) See (2)

(1) Incorporatesstressconcentrationfactor,takeKf=1.0. (2) NofatiguecheckneedbeundertakenontheweldthroatprovidedthecriteriaofB.8aremet.Theparent metalshallstillbechecked.

August 2017 B/13

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.

B/14 August 2017

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.

August 2017 B/15

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

B/16 August 2017

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

1 N/mmin t0.7πR

( ) ( ) ( )2

R2 N/mmin

0.7tπRM

0.7tR2πF

( ) ( ) )(N/mm 1R

10000.7tπR

Mτττ 22

R1/222

21R +⎟

⎠⎞

⎜⎝⎛=+=

( )( )2

1 N/mmin t0.7πR

( ) ( ) ( )2

R2 N/mmin

0.7tπRM

0.7tR2πF

( ) ( ) )(N/mm 1R

10000.7tπR

Mτττ 22

R1/222

21R +⎟

⎠⎞

⎜⎝⎛=+=

( )( )2

1 N/mmin t0.7πR

( ) ( ) ( )2

R2 N/mmin

0.7tπRM

0.7tR2πF

( ) ( ) )(N/mm 1R

10000.7tπR

Mτττ 22

R1/222

21R +⎟

⎠⎞

⎜⎝⎛=+=

( ) ( )2

yD N/mmin

32γ455fk

( )inN.ma

2Rα1M 0.6M Ruu ⎥⎦⎤

⎢⎣⎡ −=−

( )inN.m2a

2Rα1M 0.6M Rvv ⎥⎦

⎤⎢⎣

⎡−=−

Annex CDetailed Design of Flange Plates

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:

where γm istakenas1.15; c =thewidthoftheflangeplate(inmm); tf =thethicknessoftheflangeplate(inmm); ff =theyieldstressoftheflangeplate(inN/mm2).

( ) ( )2

yD N/mmin

32γ455fk

( )inN.ma

2Rα1M 0.6M Ruu ⎥⎦⎤

⎢⎣⎡ −=−

( )inN.m2a

⎤⎢⎣

⎡−=−

( ) ( )2

yD N/mmin

32γ455fk

( )inN.ma

2Rα1M 0.6M Ruu ⎥⎦⎤

⎢⎣⎡ −=−

( )inN.m2a

⎤⎢⎣

⎡−=−

( ) ( ) axis;u -ufor N.min 10γ

α12RcM3

p −−=

( ) ( ) axis; v-for v N.min 10γ

)-1(2R2cM3

p α+α−=

( ) ( ) axis;u -ufor N.min 10γ

α12RcM3

p −−=

( ) ( ) axis; v-for v N.min 10γ

)-1(2R2cM3

p α+α−=

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

)(N/mmc) 0.5 R α 0.5 a R)(0.75 α - c c(0.5

10xM 3 23

)(N/mmR) α 0.7 0.5c (aR) α - c 0.7(0.7

10xM 3 22

C/4 August 2017

Figure C.1 Typical Arrangement of Flange Plate

Note: 1. DetailsAandBaretypicalonlyandmaybeusedwithcircularoroctagonalcolumnsifrequired. 2. R=meanradiusasdefinedinBSEN40-3-3(Figure3). 3. ‘*’:Radiusofcentrallylocatedholeshallnotexceed0.3R.

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

D/2 August 2017

Annex D Determination of Shape Coefficients by Testing