BS 8007-1987 Code of practice for design of concrete structures for retaining aqueous liquids-欧标美标日标

BS

BRITISHSTANDARD

Codeofpracticefor

Designofconcrete

structuresforretainingaqueousliquids

UDC624.953:621.642.3.031:691.32:614.8

8007:1987

BS8007:1987

ThisBritishStandard,havingbeenpreparedunderthe

directionoftheCivil

EngineeringandBuildingStructuresStandards

Committee,waspublishedundertheauthorityoftheBoardofBSIandcomes

intoeffecton

30October1987.©BSI11-1998

ThefollowingBSIreferencesrelatetotheworkonthis

standard:

CommitteereferenceCSB/60

Draftforcomment86/12222DC

ISBN058016134X

CommitteesresponsibleforthisBritishStandard

ThepreparationofthisBritishStandardwasentrustedbytheCivil

EngineeringandBuildingStructuresStandardsCommittee(CSB/-)toTechnicalCommitteeCSB/60,uponwhichthefollowingbodieswererepresented:

DepartmentoftheEnvironment(PropertyServicesAgency)HealthandSafetyExecutive

InstitutionofCivilEngineers

InstitutionofStructuralEngineersWaterAuthoritiesAssociation

Amendmentsissuedsincepublication

Amd.No.

Dateofissue

Comments

BS8007:1987

©BSI11-1998i

Contents

PageCommitteesresponsibleInsidefrontcover

ForewordiiiSection1.General

1.1Scope1

1.2Fieldofapplication1

1.3Symbols1

1.4Operationalsafety1

1.5Statutoryrequirements1Section2.Design:objectivesandgeneralrecommendations

2.1Designobjectives2

2.2Structuraldesign2

2.3Loads3

2.4Analysisofwallsandjunctions3

2.5Siteconditions4

2.6Causesandcontrolofcracking4

2.7Designlifeandserviceability5

2.8Specification7

2.9Operationalsafetyconsiderations7Section3.Designanddetailing:reinforcedconcrete

3.1General8

3.2Design8Section4.Designanddetailing:prestressedconcrete

4.1General10

4.2Basisofdesign10

4.3Cylindricalprestressedconcretestructures10

4.4Otherprestressedconcretestructures10Section5.Design,detailingandworkmanshipofjoints

5.1General11

5.2Typesofjoint11

5.3Movementjoints11

5.4Constructionjoints13

5.5Temporaryopensections14

5.6Jointsingroundslabs14

5.7Jointsinwalls14

5.8Jointsinroofs14Section6.Concrete:specificationandmaterials

6.1General16

6.2Materials16

6.3Mixproportions16

6.4Workability16

6.5Surfacefinishofconcrete16

6.6Blindinglayer16

6.7Pneumaticallyappliedmortar16Section7.Specificationandworkmanship:reinforcement

7.1General177.2Specialreinforcement17

BS8007:1987

ii©BSI11-1998

PageSection8.Specificationandworkmanship:prestressingtendons

8.1General18Section9.Inspectionandtestingofthestructure

9.1General19

9.2Testingofstructures199.3Testingofroofs19

AppendixACalculationofminimumreinforcement,crackspacingand

crackwidthsinrelationtotemperatureandmoistureeffects20

AppendixBCalculationofcrackwidthsinmatureconcrete26

AppendixCJointingmaterials27

AppendixDBibliography30

Figure5.1—Examplesofmovementjoints15

FigureA.1—Surfacezones:wallsandsuspendedslabs21

FigureA.2—Surfacezones:groundslabs22

FigureA.3—RestraintfactorRforvariouswallandfloorslabplacing

sequences25

Table3.1—Allowablesteelstressesindirectorflexuraltensionfor

serviceabilitylimitstates9

Table5.1—Designoptionsforcontrolofthermalcontractionand

restrainedshrinkage13

TableA.1—Factorsforthecalculationofminimumreinforcementfor

crackdistributionandcrackspacing21

TableA.2—TypicalvaluesofT1forOPCconcretes,wheremore

particularinformationisnotavailable24

TableA.3—Influenceofslabproportionsonthecentreline

restraintfactor26PublicationsreferredtoInsidebackcover

BS8007:1987

©BSI11-1998iii

Foreword

ThisBritishStandardhasbeenpreparedunderthedirectionoftheCivil

EngineeringandBuildingStructuresStandardsCommittee.ItreplacesBS5337,whichiswithdrawn.

FollowingthewithdrawalofCP114thealternativemethodofdesignallowedinBS5337hasbeenomittedinthisBritishStandard.Secondly,thewithdrawalofCP110anditsreplacementbyBS8110haveledtotheupdatingofthiscodetoalignwithBS8110.OneimportantchangeisthatthecrackwidthequationshavebeenmodifiedtoalignwiththerecommendationsofBS8110andnowincludeacrackwidthequationfordirecttension.Otherchangesincludeamorelogical

arrangementofobjectivesandgeneralrecommendationsfordesign,the

introductionofarestraintfactor,theintroductionofrecommendationsfor

partiallyprestressedconcretestructures,improvedrecommendationsforjoints,updatingofguidanceonjointingmaterials,anelaborationofthe

recommendationsforconcreteandreinforcement(includingspecial

reinforcement),andarevisionoftheinspectionandtestingrecommendationsforthestructure.

ForthefirsttimeinaBritishStandardcivilengineeringdesigncodethedesignerisrecommendedtoconsideroperationalsafetyandtoprovideappropriatelyatthedesignstage.

Ithasbeenassumedinthedraftingofthiscodethatthedesignofliquid-retainingreinforcedandprestressedconcretestructuresisentrustedtocharteredcivilorstructuralengineersexperiencedintheuseofreinforcedorprestressedconcrete,andthatsiteconstructioniscarriedoutunderthedirectionofacompetent

person.

Thiscode,whichisatype11)designcode,hasbeenpreparedbyaTechnical

Committeeconsistingofcharteredengineersnominatedbytheorganizationsrepresented(seethebackcover).ThemembersoftheDraftingPanel,convenedbytheInstitutionofStructuralEngineers,wereasfollows.

MrRDAnchorBSc,CEng,FIStructE,FICEChairman

MrAHAllenMA(Cantab),BSc,CEng,FIStructE,FICE

ProfessorBPHughesBSc(Eng),DSc,PhD,CEng,FIStructE,MICE

MrDWQuinionBSc(Eng),CEng,FIStructE,FICEMrEHThorpeCEng,MIStructE

MrRJWMilneBScSecretary

TheworkoftheDraftingPanelwasoverseenbytheSteeringGroupfromtheTechnicalCommittee,whosemembersincludedthefollowing.

MrCJEvansMA(Cantab),FEng,FIStructE,FICE,FIWESChairmanMrHBGouldCEng,FIStructE,FICE

MrITMillarBSc,CEng,MICE

MrEMO’LearyBE,CEng,FIStructE,FICE,MIHTMrKRoweCEng,MICE,FBIM,MIWES

NOTEThenumbersinsquarebracketsusedthroughoutthetextofthisstandardrelatetothebibliographicreferencesgiveninappendixD.

1)Type1codesaredefinedinPD6501-1as“thosedetailingprofessionalknowledgeorpractices”.

BS8007:1987

iv©BSI11-1998

ABritishStandarddoesnotpurporttoincludeallthenecessaryprovisionsofacontract.UsersofBritishStandardsareresponsiblefortheircorrectapplication.

CompliancewithaBritishStandarddoesnotofitselfconferimmunityfromlegalobligations.

Summaryofpages

Thisdocumentcomprisesafrontcover,aninsidefrontcover,pagesitoivpages1to30,aninsidebackcoverandabackcover.

Thisstandardhasbeenupdated(seecopyrightdate)andmayhavehad

amendmentsincorporated.Thiswillbeindicatedintheamendmenttableontheinsidefrontcover.

BS8007:1987

©BSI11-19981

Section1.General

1.1Scope

ThisBritishStandardprovidesrecommendationsforthedesignandconstructionofnormalreinforcedandprestressedconcretestructuresusedforthe

containmentorexclusionofaqueousliquids.Theterm“liquid”inthiscodeincludesanycontainedorexcludedaqueousliquidsbutexcludesaggressiveliquids.Thecodedoesnotcoverdams,pipes,

pipelines,linedstructures,orthedamp-proofingofbasements.Theterm“structure”isusedhereinforthevesselthatcontainsorexcludestheliquid,andincludestanks,reservoirs,andothervessels.

NOTE1Thedesignofstructuresofspecialformorinunusualcircumstancesisamatterforthejudgementofthedesigner.

NOTE2Thetitlesofthepublicationsreferredtointhisstandardarelistedontheinsidebackcover.

1.2Fieldofapplication

ThisBritishStandardappliesparticularlytoUK

conditions,andalthoughtheprinciplesare

applicabletodesigninotherpartsoftheworld,thedesignershouldtakeaccountoflocalconditions,

particularlyvariationsinclimateandthepossibilityofearthquakes,whichhavenotbeenconsideredforUKconditions.Considerationhasbeengiventothestorageofliquidsatambienttemperaturesorat

temperaturesuptoapproximately35°Csuchasarefoundinswimmingpoolsandindustrialstructures.

Recommendationsaregivenforstructuresin

aggressivesoilsandforstructuresinareasliabletosettlementandsubsidence.Norecommendationshavebeenmadefortheeffectofanydynamicforcesnorfortheeffectoficeformationonthestructure,andthedesignershouldrefertospecialistliteratureforinformation.

1.3Symbols

ForthepurposesofthisBritishStandardthesymbolsgiveninBS8110-1:1985apply.

1.4Operationalsafety

Thecodeincludesrecommendationsfordesigntoprovideforoperationalsafety.

1.5Statutoryrequirements

2)

Designersshouldcheckcompliancewithany

statutoryrequirements.

2)ReferenceshouldbemadetotheReservoirsAct1975forstructuresthathaveacapacityofmorethan25000m3.

BS8007:1987

2©BSI11-1998

Section2.Design:objectivesandgeneralrecommendations

2.1Designobjectives

Thepurposeofdesignistheachievementof

acceptableprobabilitiesthatthestructurebeing

designedwillnotbecomeunfitinanywayfortheuseforwhichitisintended.Thiscodeprovidesforamethodofdesignbasedonlimitstatephilosophythatisgenerallyinaccordancewiththemethods

employedinBS8110.Structuralelementsthatarenotpartoftheliquid-retainingstructureshouldbedesignedinaccordancewithBS8110.

2.2Structuraldesign

2.2.1Limitstaterecommendations

Thedesignofthewholestructureandallindividualmembersshouldbeinaccordancewiththe

recommendationsgiveninBS8110asmodifiedbytherecommendationsofthiscode.Whenallrelevantlimitstatesareconsidered,thedesignshouldleadtoanadequatedegreeofsafetyandserviceability.

Itisrecommendedthatthesizeoftheelementsandtheamountsofreinforcementareassessedonthebasisoftheserviceabilitycrackwidthlimitstate,andthatotherlimitstates,includingtheultimatelimitstates,arechecked.

2.2.2Ultimatelimitstates(ULS)

Thepartialsafetyfactor,gf,forretainedliquidloadsshouldbetakenas1.4(asgiveninTable2.1of

BS8110-1:1985)forloadcombinations1and2andas1.2forloadcombination3,asappropriate.3)

2.2.3Serviceabilitylimitstates(SLS)

2.2.3.1General.Thepartialsafetyfactor,gf,forallloadsshouldbetakenasunityasimpliedin3.3ofBS8110-2:1985.

2.2.3.2Flotation.Astructuresubjectto

groundwaterpressureshouldbedesignedtoresistflotation.Thedeadweightoftheemptystructurewithanyanchoringdevicesshouldprovideasafetyfactorofnotlessthan1.1againstupliftpressuresduringconstructionandinservice.Afactorof1.1shouldbeusedonlywherethemaximum

groundwaterlevelcanbeassessedaccurately;otherwisethefactorshouldbeassessedbythedesigner.Theupliftmaybereducedby:

a)providingeffectivedrainagetopreventabuild-upofexternalwaterasfaraslocal

conditionspermit;

b)providingpressurereliefdevicesdischargingintothevessel(wheretheentryofexternal

groundwaterisacceptable).

2.2.3.3Cracking.Forthepurposeofdefiningthe

serviceabilitycrackwidthlimitstate,themaximumdesignsurfacecrackwidthsfortheexposure

conditionsdefinedin2.7.3shouldbetakentobethefollowing.

a)Reinforcedconcrete.Themaximumdesign

surfacecrackwidthsfordirecttensionand

flexureorrestrainedtemperatureandmoistureeffectsare:

1)severeorverysevereexposure:0.2mm;

2)criticalaestheticappearance:0.1mm.

b)Prestressedconcrete.Exceptforthespecial

recommendationsforthedesignofcylindrical

prestressedstructures(see4.3),thetensilestressintheconcreteshouldbelimitedforprestressedconcretestructuresinaccordancewiththe

recommendationsof2.2.3.4.2ofBS8110-1:1985.Astaticallydeterminatemembernominally

subjectedtoaxialprestressingshouldbe

assumedtohaveaminimumeccentricityof

prestressingof20mmor0.05timestheoverallthicknessintheplaneofbending,whicheverisless.Forstaticallyindeterminatestructures,

includingcylindricalprestressedstructures,thisminimumeccentricityrecommendationcanbeignored.

Therequiredexposureconditionsforthesurfacesofallmembersshouldbeclearlydefinedattheoutsetofthedesignprocessandeachmemberdesignedinaccordancewiththecrackwidthlimitstate

recommendationsinthissection.

Guidanceonassumptionsandmethodsthatmaybeusedforcalculatingcrackwidthsaregivenin2.6andappendicesAandB.

3)Inexceptionalcircumstanceswhereitisenvisagedthattheheightoftheliquidcangreatlyexceedtheheightofthewall,factorsderivedfrom2.2.2ofBS8110-2:1985shouldbeconsidered.

Section2BS8007:1987

©BSI11-19983

2.2.3.4Deflections.Therecommendationsfor

span/effectivedepthratiosgiveninBS8110-1:1985applytohorizontalmemberscarryinguniformly

distributedloads.Foracantileverwallwhichtapersuniformlyawayfromthesupportandwhichis

loadedwithatriangularpressure,anetreductionfactorshouldbeappliedtotheaboveratiosifthethicknessatthetopislessthan0.6timesthe

thicknessatthebase.Thisreductionfactorcanbeassumedtovarylinearlybetween1.0and0.78

wherethethicknessatthetopvaries

between0.6and0.3timesthethicknessatthe

bottom.Inaddition,allowanceshouldbemadeforthesignificantadditionaldeflectionwhichoccursatthetopofthewallduetorotation,ifthepressuredistributionunderthebaseistriangularorvery

asymmetricallytrapezoidal.Limitsfordeflectionswillnormallybethosefornon-liquid-retaining

structuressinceonlyinexceptionalcircumstanceswilldeflectionsbemorecriticalwithregardto

freeboard,drainageorredistributionofload.

Retainingwallsshouldbebackfilledinevenlayersaroundthestructure,thethicknessofthelayers

beingspecifiedbythedesigner.Overcompaction

adjacenttothewallshouldbeavoidedotherwise

largedifferentialdeflections(andsliding)ofthewallmayoccur.

Atleast75%oftheliquidloadshouldbeconsideredaspermanentwhencalculatingdeflections.

2.3Loads

Allstructuresrequiredtoretainliquidsshouldbedesignedforboththefullandemptyconditions,andtheassumptionsregardingthearrangementof

loadingshouldbesuchastocausethemostcriticaleffects.Particularattentionshouldbepaidto

possibleslidingandoverturning.

Liquidloadsshouldallowfortheactualdensityofthecontainedliquidandpossibletransient

conditions,e.g.suspendedordepositedsiltorgritwhereappropriate.Forultimatelimitstate

conditions,liquidlevelsshouldbetakentothetopsofwallsassumingthattheliquidoutletsare

blocked.Forserviceabilitylimitstateconditionstheliquidlevelshouldbetakentotheworkingtop

liquidlevelortheoverflowlevelasappropriatetoworkingconditions.

Allowanceshouldbemadefortheeffectsofany

adversesoilpressuresonwalls,accordingtothe

compactionand/orsurchargeofthesoilandthe

conditionofthestructureduringconstructionandinservice.Noreliefshouldbegivenforbeneficialsoilpressureeffectsonthewallsofcontainment

structuresinthefullcondition.Thermalexpansionofaroofshouldbeminimizedbyreflectivegravelorotherprotectionagainstsolarradiation.Anexampleofacriticaladverseloadingeffectoccurswhen

thermalexpansionofaroofforcesthewallsofanemptystructureintothesurroundingbackfill.Inthiscasethepassivesoilpressureonthewallsmaybelimitedbyinsertionofathicknessof

compressibleanddurablematerialand/orby

providingaslidingjointbetweenthetopofthewallandtheundersideoftheroof.Thiscanbeeitheratemporaryfreeslidingjointthatisnotcastintoafixedorpinnedconnectionuntilreflectivegravelorothersolarprotectivematerialisplacedontheroof,orapermanentlyslidingjointofassessedlimitingfriction.Movementofaroofmayoccuralsowheretherearesubstantialvariationsinthetemperatureofthecontainedliquid.Wherearoofisrigidly

connectedtoawallthismayleadtoadditional

loadinginthewallthatshouldbeconsideredinthedesign.Earthcoveringonreservoirroofsmaybe

takenasdeadload,butdueaccountshouldbetakenofconstructionloadsfromplantandheapedearth,whichmayexceedtheintendeddesignload.

2.4Analysisofwallsandjunctions

Theliquidpressureonplanewallsmayberesistedbyacombinationofhorizontalandverticalbendingmoments.Anassessmentshouldbemadeofthe

proportionsofthepressuretoberesistedbybendingmomentsintheverticalandhorizontalplanes.

Allowanceshouldalsobemadefortheeffectsof

directtensioninwallsinducedbyflexuralactioninadjacentwalls.Reinforcementshouldbeprovidedtoresisthorizontalbendingmomentsatallcorners

wherewallsarerigidlyjoined.

Cylindricalstructuresmaybeconstructedwithafixed,pinnedorslidingjointbetweenthewallsandthefoundationslab.Allowanceshouldbemadeforthecalculatedflexuralactionsandhooptensions.Sectionsshouldbecheckedforshearresistance.

BS8007:1987Section2

4©BSI11-1998

2.5Siteconditions

2.5.1Groundmovement

Groundmovementleadingtodisplacementand

crackingofliquid-retainingstructuresmaycausesevereleakage.Thedesignershouldtherefore

considerthepossibilityofgeologicalfaults,miningandotherconditionsgivingrisetofoundation

conditionswherethebearingstratahavevaryingdegreesofcompressibility.Whenitisnotpossibletoavoidsiteswheresuchconditionsoccur,the

designershouldconsideradoptingoneormoreofthefollowingmeasures:

a)dividingthewholestructureintosmallercompartmentsinordertoreducethelikelydifferentialmovementineachcompartment;

b)providingspeciallydesignedjointsinthestructuretofacilitatemovement;

c)usingprestressingtechniquestoactasasafeguardagainstcracking;

d)providingflexiblesectionsinservicepipes;

e)inminingareas,providingaformoffoundationthatwillreduceanyhorizontalforcesfrom

groundmovement;

f)providingunderfloordrainagetoprevent

possibleupliftpressuresonfloorsandwallbaseswheregroundwaterisnotconsideredinthe

design,forexample,whereonlyonecompartmentofatwo-compartmentstructureisfilledand

leakageoccurs.

Othermeasuresmayalsobenecessarydependingonthepredictedde