·1·

Foreword

ThiscodeisdevelopedbySinopecLuoyangEngineeringCo.,Ltd.incooperationwithotherinvolvedorganizationsbasedontherequirementsofDocumentJIANBIAO〔2009〕No.88issuedbytheMinistryofHousingandUrban-RuralDevelopment-NoticeonPrintingtheDevelopmentandRevisionPlanofNationalEngineeringConstructionStandardsin2009.

Thiscodeisprepared,reviewedandfinalizedbythedevelopmentteambasedonwideandextensiveinvestigationsandstudies,summarizedpractices,requestedcommentsaswellasreferencestotheinternationalcodesandadvancedforeignexperience.

Thiscodecomprises7chaptersand2appendixes,andmainlyincludesGeneralProvisions,Terms,BasicRequirements,ClassificationofPollutionPreventionArea,Design,Materials,ConstructionandQualityInspection.

TheMinistryofHousingandUrban-RuralDevelopmentofthePeople'sRepublicofChinaisinchargeoftheadministrationofthiscode.ChinaPetroleumandChemicalCorporation(SinopecGroup)isresponsibleforitsroutinemanagement.SinopecLuoyangEngineeringCo.,Ltd.isinchargeoftheexplanationoftechnicalspecifications.Ifanycommentsorrecommendationsareproposedinimplementationofthiscode,pleasesendyourlcomments/recommendationstotheNationalStandardManagementTeamofSinopec-LuoyangEngineeringCo.,Ltd.forthiscode(Address:No.27ZhongzhouWestRoad,LuoyangCity,HenanProvince,P.R.China,PostCode:471003)forreferenceinfuturerevisions.

Chiefdevelopmentorganization,co-developmentorganization,participatingdevelopment

organization,chiefdrafterandchiefreviewerofthecode:

ChiefDevelopmentOrganization:

SinopecLuoyangEngineeringCo.,Ltd

Co-DevelopmentOrganization:

SinopecEngineeringIncorporation

SinopecNingboEngineeringCo.,Ltd

ChinaHuanqiuContractingandEngineeringCorp

CPECCEastChinaDesignBranch

ChinaChengdaEngineeringCo.,Ltd

CNPCQingyangPetrochemicalCompany

CNPCSichuanPetrochemicalCo.,Ltd

SichuanZisenEnvironmentalProtectionTechnologyCo.,Ltd

BeijingGeoEnvironEngineeringandTechnologyInc.

BeijingSinomaBauchemTechnologyCo.,Ltd

SolmaxInternationalInc.

GSEEnvironmentalLiningTechnology(Suzhou)Co.,Ltd

BeijingJinyuhuaTechnologyandTradingCo.,Ltd

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ParticipatingDevelopmentOrganization:

DowCorning(China)InvestmentCo.,Ltd

BeijingTruheroEnvironmentalProtectionTechnologyCo.,Ltd

BeijingKoesterInternationalChemistryCo.,Ltd

ChiefDrafter:

WuXiaopingJiZhuanpingShenManduiWangSongshengZhangLinqingChenWeiHuangZhongxiZhouJiaxiangWangYaodongYangXiaohongGeBaofengCuiZhongtaoYangShiyongWeiZhizhongZhangDongjie

ZhangChengwuJiangJixiangQiuShiLiuZhongyuanYangXiaoyongYangHuiLiuYongLiuJiwuHuangShichangCaoDawei

TanXiaomingQiChangweiGaoJianqiuLiJianliuWangWenkaiDuXinhuiYangJianping

ChiefReviewer:

HuangZuojianJiangHongQiuZhenghuaSuJunweiLiYuan

LiXuanminHanGenrongXuZhiqiLiLichangWangChao

WangNingyangHuangYuenianRenYiTangJianZhaoFuyun

Contents

1GeneralProvisions (1)

2Terms (2)

3BasicRequirements (3)

4ClassificationofPollutionPreventionArea (4)

5Design (7)

5.1GeneralRequirements (7)

5.2Paving (7)

5.3TankFarm (10)

5.4Basin,WastewaterDitchandVariousWells (11)

5.5UndergroundPiping (13)

6Materials (15)

7ConstructionandQualityInspection (17)

7.1GeneralRequirements (17)

7.2ClayImpermeableLayer (17)

7.3ConcreteImpermeableLayer (17)

7.4HDPEGeomembraneImpermeableLiner (18)

7.5SodiumBentoniteGeosyntheficClayLiner (19)

7.6UndergroundPiping (20)

AppendixAClassificationofRelevantCharacteristicsofConstructionSite (21)

AppendixBMethodforAirPressure,Vacuum,DestructiveandSparkTest (23)

ExplanationofWordinginThisCode (24)

QuotedStandardList (25)

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1GeneralProvisions

1.0.1Thiscodeisdevelopedtoimplementrelevantnationalpoliciesinthedesign,constructionandqualityinspectionofanti-seepageinpetrochemicalengineering,toprotectthegroundwaterenvironment,tostandardizetechnicalrequirements,andtoachievesafetyandapplicability,advancedtechnologyandcost-effectiveness.

1.0.2Thiscodeisapplicabletothedesign,constructionandqualityinspectionofanti-seepageforthepetrochemicalandcoalchemicalengineering,butitisnotapplicabletothestorage,disposalandlandfillofnormalindustrialsolidwastesandhazardouswastes,andinstallationoflong-distancepipelines.

1.0.3Inadditiontotherequirementsstipulatedinthiscode,design,constructionandqualityinspectionofanti-seepageinpetrochemicalengineeringsshallalsocomplywiththosestipulatedinthecurrentrelevantstandardsofthenation.

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2Terms

2.0.1Impermeablebarrier

Acombinationofimpermeablematerialandconstructiontobuildabarrieragainstleakageofcontaminants.

2.0.2Vadosezone

Azonebetweenthegroundsurfaceandthephreaticwatertable.

2.0.3Phreatic

Subsurfacegroundwaterabovethefirststableaquicludehavingafreewatersurface.

2.0.4Contractionjoint

Ajointinstalledtopreventoccurrenceofanyirregularcracksintheconcretepavingcausedbyanydropinambienttemperature.

2.0.5Expansionjoint

Ajointinstalledtopreventoccurrenceofanycrushorarchintheconcretesurfacecausedbyanyriseinambienttemperature.

2.0.6Miniorpollutionpreventionarea

Anareaorlocationwhereanyleakageofmaterialsorcontaminantspollutivetothegroundwaterenvironmentmaybetimelydetectedanddisposedof.

2.0.7Mainpollutionpreventionarea

Anareaorlocationwhereanyleakageofmaterialsorcontaminantspollutivetothegroundenvironmentcannotbetimelydetectedanddisposedof.

2.0.8Non-pollutionpreventionarea

Anareaorlocationotherthanaminiorpollutionpreventionareaandamainpollutionpreventionarea.

2.0.9Primaryundergroundpiping

Undergroundpipingarrangedoutsidethebatterylimitofeachunitintheplantandusedtocollectandtransportthewastewaterfromeachunittothewastewatertreatmentplant(orthewastewaterliftingunit).

2.0.10Secondaryundergroundpiping

Undergroundpipingusedtoconnecteachunitintheplantwiththeprimaryundergroundpiping,unitwastewaterliftingsump,undergroundsloptankandundergroundsolventtank.

2.0.11Tertiaryundergroundpiping

Otherundergroundbranchpipingconnectedwiththesecondaryundergroundpiping.

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3BasicRequirements

3.0.1Theanti-seepagedesignfortheconstructionprojectsshallmeettherequirementsspecifiedintheEIA(environmentalimpactassessment)approvaldocumentandtheEIAreport.

3.0.2Priortothestartoftheanti-seepagedesign,thegeologicalandhydrogeologicaldataoftheprojectshallbefamiliarizedwith,andtheinformationonthesensitivityofthegroundwaterenvironmentinthesite,thepollutioncharacteristicsoftheaquiferandtheantifoulingpropertiesofthevadosezoneshallbecollectedandstudied.

3.0.3Propermeasuresshallbetakenfortheconstructionprojectstopreventandreduceaccidentalreleasing,emitting,drippingandleakingofcontaminants.

3.0.4Intheanti-seepagedesign,respectiveanti-seepageschemesshallbeadoptedbasedontheclassificationofpollutionpreventionarea.

3.0.5Appropriatemeasuresshallbetakentopreventthespreadofcontaminantsfromapollutionpreventionareatoanon-pollutionpreventionarea.

3.0.6Theimpermeablebarriershallbemadeofthematerialinapermeabilitycoefficientnotlargerthan1.0×10??cm/sandcompatiblewithmaterialsorcontaminantsincontact.

3.0.7Thesubgradeoftheimpermeablebarriershallbeuniform.

3.0.8Theimpermeablematerialandconstructiontechnologyusedshallmeettherequirementsofthehealth,safetyandenvironmental(HSE),

3.0.9Theconstructiontechnicalpeopleshallbefamiliarwiththetechnicalrequirementsandqualitystandardsforanti-seepageintheproject.

3.0.10Intheprocessofconstruction,thespeciallyappointedpersoninchargeofqualitycontrolandconstructionrecordsisnecessary.

3.0.11Foranti-seepagedesign,no-pollutionshallbeguaranteedtothegroundwaterwithinthedesignworkinglife.Whenthedesignworkinglifeexpires,theimpermeablebarriershallbesubjecttoinspectionandverification,onlythequalifiedonecanbefurtherused.

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4ClassificationofPollutionPreventionArea

4.0.1Intheearlystageoftheproject,thenecessityforadoptionofanyanti-seepageshallbeanalyzedaccordingtothesensitivityofthegroundwaterenvironment,pollutioncharacteristicsoftheaquiferandantifoulingpropertiesofthevadosezoneasthosespecifiedinTable4.0.1.Theclassificationofthesensitivityofthegroundwaterenvironment,pollutioncharacteristicsoftheaquiferandantifoulingpropertiesofthevadosezoneshallbeinaccordancewiththosespecifiedinAppendixA.

Table4.0.1Judgementofanti-seepageforconstructionsite

Sensitivityofgroundwaterenvironment

Pollutioncharacteristicsofaquifer

Antifoulingpropertiesofvadosezone

Anti-seepagenecessity

Low

Noteasy-easy

Low-high

N/A

Medium

Noteasy

Low-high

N/A

Medium

High

N/A

Easy

High

Need

Medium-easy

Low-medium

Need

High

Noteasy-easy

Low-high

Need

4.0.2Accordingtothecharacteristics,areasclassificationandlocationsoftheprocessplants/units,theconstructionsitemaybeclassifiedintonon-pollutionpreventionareas,miniorpollutionpreventionareasandmainpollutionpreventionareas.

4.0.3TypicalclassificationofpollutionpreventionareaswithinthepetrochemicalunitshallbeinaccordancewiththosespecifiedinTable4.0.3.

Table4.0.3Typicalclassificationofpollutionpreventionareainpetrochemicalunit

Plant/Unit

Pollutionpreventionareaandlocation

Classificationofpollutionpreventionarea

Undergroundpiping

Undergroundpipingforindustrialwastewater(InitialRainwater),slopoilandvariousspentsolvents

Mainarea

Undergroundtank

Bottomslabandwalloffoundationforvariousundergroundsloptanks,spentsolventtanks,causticsludgetanksandolefintanksetc.

Mainarea

Industrialwastewaterpitsandwastewaterbasins

Bottomslabandwallofindustrialwastewaterinspectionwell,waterseal

well,leachateinspectionwell,wastewaterbasinandinitialrainwater

liftingbasin

Mainarea

Industrialwastewaterpretreatment

Bottomslabandwallofindustrialwastewaterpretreatmentbasin

Mainarea

Cokestoragebasin

Bottomslabandwallofcokestoragebasin

Mainarea

Liquidsulfurstoragesump

Bottomslabandwallofliquidsulfurstoragesump

Miniorarea

Industrialwastewaterditch

Bottomslabandwallofpumpinterceptingditch,oilstation,

demineralizedwaterstationinterceptingditchandopenindustrial

wastewaterditch

Miniorarea

Paving

一

Miniorarea

·5·

4.0.4TypicalclassificationofpollutionpreventionareawithinthestorageandtransportationareaofthepetrochemicalplantshallbeinaccordancewiththosespecifiedinTable4.0.4.

Table4.0.4Typicalclassificationofpollutionpreventionareainstorageand

transportationareaofpetrochemicalplant

Plant/Unit

Pollutionpreventionareaandlocation

Classificationofpollution

preventionarea

TankFarmforfeedstock,

lightproductoilandliquid

chemicaletc.

Ringwallandslopetypetankfoundation

Mainarea

Tankfoundationwithconcreteslabtype

Miniorarea

Pavingareaoftankfarmandfiredike

Miniorarea

Oilpumpandproductoilmeteringstation

Pavingareaoftheoilpumpandproductoilmeteringstation

Miniorarea

Railwayandtruckloading/unloading

Pavingareaofloading/unloadingplatform

Miniorarea

Oilgasrecoveryfacility

Pavingareaoftheoilgasrecoveryfacility

Miniorarea

Railwaytankcarwashingstation

Pavingareaofthetankwashingstation

Miniorarea

Undergroundtank

Bottomslabandwalloffoundationforundergroundcondensatetank,sloptankandspentsolventtanketc.

Mainarea

Undergroundpiping

Undergroundpipingforindustrialwastewater,slopoilandspentsolventetc

Mainarea

Utilitypiperack

Centralizedvalvepavingareaofutilitypiperack

Miniorarea

Note:Thetankfarmforfeedstock,lightproductoilandliquidchemicaleteshallnotincludetanksforliquidsulfur,asphalt,heavyresidualandspheresforliquidhydrocarbons.

4.0.5TypicalclassificationofpollutionpreventionareawithintheutilitiesareaofthepetrochemicalplantshallbeinaccordancewiththosespecifiedinTable4.0.5.

Table4.0.5Typicalclassificationofpollutionpreventionareain

utilitiesareaofpetrochemicalplant

Plant/Unit

Pollutionpreventionareaandlocation

Classificationof

pollution

preventionarea

Powerstation

Ashstoragesump

Bottomslabandwallofashstoragesumpandashsluiceway

Mainarea

Boileremergencyoilsump

Bottomslabandwallofemergencyoilsump

Mainarea

Blowdownsumpandpit

Bottomslabandwallofblowdownsumpandpit

Mainarea

Substation

Accidentoilsump

Bottomslabandwallofaccidentoilsump

Mainarea

Waterchemical

treatment

station

Acid/alkalitankfarm

Ringwallandslopetypetankfoundation

Mainarea

Tankfoundationwithconcreteslabtype

Miniorarea

Pavingareaofacid/alkalinetankfarmandcofferdam

Miniorarea

Neutralizationsumpandwastewaterditch

Bottomslabandwallofneutralizationsumpandwastewaterditch

Mainarea

Watertreatmentbuliding

Pavingareawithinthewatertreatmentbuilding

Miniorarea

·6·

Table4.0.5(continued)

Plant/Unit

Pollutionpreventionareaandlocation

Classificationof

pollution

preventionarea

Coolingwater

plant

Sewagesump

Bottomslabandwallofsewagesump

Mainarea

Coolingtowerbottomwaterbasinandsuctionwaterbasin

Bottomslabandwalloftowerbottomwaterbasinandsuctionwaterbasin

Miniorarea

Dosingroom

Indoorpaving

Miniorarea

Rainwatermonitoringbasin

Bottomslabandwallofrainwatermonitoringbasin

Miniorarea

Accidentbasin

Bottomslabandwallofaccidentbasin

Miniorarea

Wastewater

treatmentplant

Undergroundindustrialwastewaterpiping

Undergroundindustrialwastewaterpiping

Mainarea

Regulatingtank,oil

separatingtankandsloptank

Ringwallandslopetypetankfouncdation

Mainarea

Tankfoundationwithconcreteslabtype

Miniorarea

Pavingareaoftankfarmandfiredike

Miniorarea

Industrialwastewater,slop

oilandsludgebasin,

sedimentationbasinand

wastewaterwell

Bottomslabandwallofregulatingbasin,equalizationbasin,oil

interceptorbasin,floatationbasin,septicbasin,slopoilcollecting

pit,oilysludgebasin,scumbasin,sedimentationbasinandsludge

pit;bottomslabandwallofinspectionwell,watersealwelland

leachateinspectionwell

Mainarea

Sludgestoragesump

Bottomslabandwallofsludgestoragesump

Mainarea

Sludgeincineration

Pavingwithintheboundaryofthesludgeincinerationarea

Miniorarea

4.0.6TypicalclassificationofpollutionpreventionareawithintheauxiliaryworkareaofthepetrochemicalplantshallbeinaccordancewiththosespecifiedinTable4.0.6.

Table4.0.6Typicalclassificationofpollutionpreventionareain

auxiliaryworkareaofpetrochemicalplant

Plant/Unit

Pollutionpreventionareaandlocation

Classificationofpollutionpreventionarea

Watersolublebulkrawmaterialandproductwarehouse

Warehousepaving

Miniorarea

Liquidchemicalswarehouse

Indoorpavingofchemicalswarehouse

Miniorarea

·7·

5Design

5.1GeneralRequirements

5.1.1Theprojectanti-seepagedesignshallbeinaccordancewiththefollowingrequirements:

1Thedesignworkinglifeofanti-seepageforthepetrochemicalequipments,undergroundpipings,buildingsandspecialstructuresshallnotbelowerthanthedesignworkinglifeofthemainbody.

2Forminiorpollutionpreventionareas,theanti-seepageperformanceoftheimpermeablebarriersshallnotbelowerthanthatoftheclaylayerin1.5mthicknessandwithapermeabilitycoefficientof1.0×10??cm/s.Formainpollutionpreventionareas,theanti-seepageperformanceoftheimpermeablebarriersshallnotbelowerthanthatoftheclaylayerin6.0mthicknessandwithapermeabilitycoefficientof1.0×10??cm/s.

5.1.2Theimpermeablebarriermaybefromasingleimpermeablematerialormultipleimpermeablematerials.

5.1.3Underdryclimaticconditions,sodiumbentonitegeosyntheticclaylinershallnotbeadopted.

5.1.4Thepavingofthepollutionpreventionareashallbeslopedtotheoutfallordrainageditch.

5.1.5Incaseofcorrosivecontaminants,anti-corrosiveimpermeablematerialshallbeadopted,oranti-corrosionmeasuresshallbetaken.

5.2Paving

5.2.1Thepavingimpermeable/layermaybefromclay,impermeableconcrete,highdensitypolyethylene(HDPE)geomembrane,sodiumbentonitegeosyntheticclaylinerandothermaterialswithequivalentimpermeability.

5.2.2Whentheconstructionsitehasclayinconformitywithrelevantrequirements,theclayimpermeablelayershouldbeadoptedforgroundanti-seepage.Thetopoftheimpermeablebarriershouldbeprovidedwithalayerofconcreteoralayerofgravelatleast200mmthick.

5.2.3Theconcreteimpermeablelayermaybemadeofimpermeablesteelfiberreinforcedconcrete,impermeablesyntheticfiberreinforcedconcrete,impermeablereinforcedconcreteandimpermeableplainconcrete.

5.2.4InadditiontotherelevantrequirementsinthecurrentnationalstandardCodefordesignofconcretestructuresGB50010,thedurabilityoftheconcreteimpermeablelayershallalsobeinaccordancewiththefollowingrequirements:

1TheconcreteshallhaveastrengthgradeofnotlowerthanC25,animpermeabilitygradeofnotlowerthanP6,andathicknessofnotlessthan100mm.

2Thevolumefractionofsteelfibershouldbe0.25%to1.00%.

3Thevolumefractionofsyntheticfibershouldbe0.10%to0.20%.

4ThemixproportiondesignofconcreteshallmeettherelevantrequirementsofthecurrentprofessionalstandardSpecificationformixproportiondesignofordinaryconcreteJGJ55andTechnicalspecificationforapplicationoffiberreinforcedconcreteJGJ/T221.

5.2.5Theconcreteimpermeablelayershallbeprovidedwithcontractionjointsandexpansionjointsin

·8·

accordancewiththefollowingrequirements:

1Longitudinalandtransversecontractionjointsandexpansionjointsshouldintersectatrightangles.

2ContractionjointsandexpansionjointsshallbespacedinaccordancewiththosespecifiedinTable5.2.5.

Table5.2.5Spacingbetweencontractionjointsandexpansionjoints(m)

Type

Contractionjoint

Expansionjoint

Impermeablesteelfiberreinforcedconcrete

6～9

20～30

Impermeablereinforcedconcrete

5~8

Impermeablesyntheticfiberreinforcedconcrete

4~5

Impermeableplainconcrete

3~3.5

Note:Forconstructioninsummer,thesmallervaluespecifiedinthetableshouldbetaken.

5.2.6Contractionjointsshouldbecutjoints,withthewidthofpreferably6mmto10mmandthedepthof16mmto25mm.Thedepthofcaulkingsealantsshouldbe6mmto10mm.Jointsshallbefilledwithcaulkingsealantandbackingmaterial(Figure5.2.6).Thesurfaceofthecaulkingsealantshallbebelowthepavingsurface,preferably2mmto3mmatlowtemperaturesandnolargerthan2mmathightemperatures.

Figure5.2.6Sketchofcontractionjoint

1-Cushion;2-Concreteimpermeablelayer;3-Caulkingsealant;4-Backingmaterial

5.2.7Thewidthofexpansionjointsshouldbe20mmto30mm.Thewidthtodepthratioofcaulkingsealantshouldbe2:1,andadepthof10mmto15mm.Jointsshallbefilledwithcaulkingboard,backingmaterialandcaulkingsealant(Figure5.2.7).Thesurfaceofthecaulkingsealantshallbebelowthepavingsurface,preferably2mmto3mmatlowtemperaturesandnolargerthan2mmathightemperatures.

Figure5.2.7Sketchofexpansionjoint

1-Cushion;2-Concreteimpermeablelayer;3-Caulkingboard;4-Caulkingsealant;5-BackingMaterial

5.2.8Atthejunctionbetweentheconcreteimpermeablelayerandthewall,columnorfoundation,connectingjoint(Figure5.2.8)shallbeprovidedwiththewidthofpreferably20mmto30mm.Thewidthtodepthratioofcaulkingsealantshouldbe2:1,andadepthof10mmto15mm.Jointsshallbefilledwithcaulkingboard,backingmaterialandcaulkingsealant.

·9·

Figure5.2.8Sketchofconnectingjoint

1-Cushion;2-Concreteimpermeablelayer;3-Caulkingboard;4-Caulkingsealant;5-Backingmaterial

5.2.9Thecontractionjoints,expansionjointsandconnectingjointsoftheconcreteimpermeablelayershallbesealedinaccordancewiththefollowingrequirements:

1Caulkingsealantshouldberoadsiliconesealantorotherweatherproofsealingmaterials.

2Caulkingboardshouldbeclosedcellpolyethylene(PE)foamboardorfiberboard.

3Backingmaterialshouldbeexpandedclosedcellpolyethylene(PE),polyvinylChloride(PVC)orelasticpolypropylene(PP)foamrodwithadiameterofnotlessthan1.25timesofthejointwidth.

5.2.10Nohorizontalpipingshallbeembeddedintheconcreteimpermeablelayer.Connectingjointsshallbesetincaseofanypipingpenetratingthroughthepavingvertically(Figure5.2.8).

5.2.11TheHDPEgeomembraneimpermeablelinef(Figure5.2.11)shallbeinaccordancewiththefollowingrequirements:

1TheHDPEgeomembraneshouldhaveathicknessofnotlessthan1.50mmandanembeddeddepthofnotlessthan300mm.

2Aprotectivelayershallbesetabove/underthegeomembrane,whichmaybemadeoffilamentnonwovengeotextile.Theprotectivelayerunderthegeomembranemayalsobealayerofsandfreeofsharpparticlesandathicknessofnotlessthan100mm.

3Asandlayershallbecoveredwiththeprotectivelayerabovethegeomembrane,whichshouldnotbelessthan200mmthick.

5-

Figure5.2.11SketchofHDPEliner

1-Subgrade;2-Undergeomembraneprotectivelayer;3-HDPE;4-Abovegeomembraneprotectivelayer;5-Sandlayer

5.2.12TheHDPEgeomembraneshallbeslopedtotheblindditchordrainageditch.Filamentnonwovengeotextilewrappedpebble,brokenstoneorothermaterialswithgoodimpermeabilityshouldbeusedintheblindditchfordrainage.FilamentnonwovengeotextilewrappedHDPEperforateddrainagepipemayalsobeused.

5.2.13Sodiumbentonitegeosyntheticclayliner(Figure5.2.13)shallbeinaccordancewiththefollowingrequirements:

Figure5.2.13Sketchofsodumbentonitegeosyntheticclayliner

1-Subgrade;2-Sodiumbentonitegeosyntheticclayliner;3-Sandcushion;4-Concretelayer

·10·

1TheconcretelayershouldhaveastrengthgradenotlowerthanC20andathicknessof100mm.

2Thesandcushionshouldnotbelessthan300mmthick.

3Needlepunchedlaminatingsodiumbentonitegeosyntheticclaylinershouldbeused.

5.3TankFarm

5.3.1Theimpermeablelinerfortheringwalltypetankfoundation(Figure5.3.1)shallbeinaccordancewiththefollowingrequirements:

1TheHDPEgeomembraneshouldnotbelessthan1.50mmthick.

2Aprotectivelayershallbeplacedabove/underthegeomembrane,whichmaybemadeofnonwovenfilamentgeotextile.Theprotectivelayerunderthegeomembranemaybealayerofsandfreefromsharpparticlesandwithathicknessofnotlessthan100mm.

3TheHDPEgeomembraneshallbeslopedfromthecentertotheperipheryatagradientofnotlessthan1.5%.

-Drainpipe7

Figure5.3.1SketchofHDPEgeomembraneimpermeablelinerforringwalltypetankfoundation

1-Tankfoundationfilinglayerororiginalsoilrammed;2-Undergeomembraneprotectivelayer;3-HDPEgeomembrane;

4-Abovegeomembraneprotectivelayer;5-Sandcushion;6-Asphaltsandinsulatinglayer;7-Ringwallfoundation

5.3.2Theimpermeablelayerfortheconcreteslabtypetankfoundation(Figure5.3.2)shallbeinaccordancewiththefollowingrequirements:

-Drainpipe

6-

Figure5.3.2Sketchofimpermeablelinerforconcreteslabtypetankfoundation

1-Concretecushion;2-Reinforcedconcreteslab;3-Waterproofcoating;

4-Sandcushion;5-Asphaltsandinsulatinglayer;6-Ringwall

1TheconcreteslabandtheringwallabovetheconcreteslabshallbeofimpermeableconcreteatanimpermeabilitygradeofnotlowerthanP6.

2Theinnersurfaceoftheconcreteslabandtheringwallabovetheconcreteslabshouldbe

·11·

coatedwithpolymercementandotherflexiblewaterproofcoatingstoathicknessofnotlessthan1.0mm.

3Thetopoftheconcreteslabshallbepitchedfromthecentertotheperipheryatagradient(iinFigure5.3.2)ofnotlessthan0.3%.

5.3.3ThedrainpipeplacedaroundtheringwallofthetankfoundationshouldbeofHDPE,andshallbeinaccordancewiththerelevantrequirementsinthecurrentnationalstandardCodefordesignofsteeltankfoundationGB50473.

5.3.4Whenthedrainpipeisbelowthegroundlevel,aleakagedetectionwellshallbeprovidedatthelocationofthedrainpipe.Aremovableweathersteelcovershallbeplacedonthetopoftheleakagedetectionwell.TheleakagedetectionwellshallbeinaccordancewiththefoHowingrequirements:

1Theleakagedetectionwellshouldbeinadimensionof500mm×500mmand200mmabovethepaving.Thebottomofthewellshallbe300mmbelowthedrainpipe.

2TheleakagedetectionwellshallbeofimpermeablereinforcedconcreteatastrengthgradeofnotlowerthanC30andanimpermeabilitygradeofnotlowerthanP8.

3Thewallandbottomslaboftheleakagedetectionwellshouldnotbelessthan100mmthick.

5.3.5TherequirementofpavingimpermeablelayerinsidethefiredikeofthetankfarmshallbeinaccordancewiththosespecifiedinSection5.2.

5.3.6InadditiontotherelevantrequirementsinthecurrentnationalstandardCodefordesignoffiredikeinstoragetankfarmGB50351,thedesignoffiredikeshallalsobeinaccordancewiththefollowingrequirements:

1Firedikeshoul