SERIES 500 dRaInagE and SERvIcE ductS natIOnaL aLtERatIOnS ... · PDF fileinstallation in the...

SERIES 500 dRaInagE and SERvIcE ductS

contents

Clause Title Page

501 (05/01)PipesforDrainageand ServiceDucts 2

502 ExcavationforPipesand Chambers 5

503 (11/05)Bedding,Layingand SurroundingofPipes 5

504 JointingofPipes 7

505 BackfillingofTrenchesand FilterDrains 8

506 ConnectingtoExistingDrains ChambersandChannels 10

507 (05/01)Chambers 11

#508 GulliesandPipeJunctions 12

509 TestingandCleaning 13

510 SurfaceWaterChannelsand DrainageChannelBlocks 14

511 LandDrains 14

512 BackfillingtoPipeBaysand VergesonBridges 14

513 PermeableBackingtoEarth RetainingStructures 14

514 FinDrains 14

515 NarrowFilterDrains 18

516 CombinedDrainageandKerb Systems 19

517 LinearDrainageChannelSystems 20

518 (05/01)Thermoplastics StructuredWallPipesand Fittings 21

519 (05/01)ConcreteBagwork 25

520 (05/01)TheCleaningofExisting DrainageSystems 26

521 (11/03)LowPressureHighVolume JettingofDrainageSystems 27

ManuaL OF cOntRact dOcuMEntS FOR HIgHWaY WORKS vOLuME 1 SPEcIFIcatIOn FOR HIgHWaY WORKS

Amendment-November2009 1

natIOnaL aLtERatIOnS OF tHE OvERSEEIng ORganISatIOnS OF ScOtLand, WaLES and nORtHERn IRELand

northern Ireland

Clause Title Page

508NI GulliesandPipeJunctions N1

# denotesaClauseorSampleAppendixwhichhasasubstitute NationalClauseorSampleAppendixforoneormoreofthe OverseeingOrganisationsofScotland,WalesorNorthern Ireland.

Volume1 Series500SpecificationforHighwayWorks DrainageandServiceDucts

dRaInagE and SERvIcE ductS

501 (05/01) Pipes for drainage and for Service ducts

general

1 (11/06)WherethetermdrainisusedinthisSeriesitshallbedeemedtoincludethetermssewerandpipedculvert.

TheContractorshalldesignthepipedculvertslistedinAppendix1/10inaccordancewiththerequirementsofClause106.

Series8000(MCHW5.8.2)appliestotheinstallationbytrenchlesstechniquesofhighwaydrainage,serviceducts,sleevesandculvertswithinternaldiametersuptoandincluding900mmnominalinternaldiameterorwidth.

2 (11/04)Alldrainsconstructedofpipesaswellaspipedculvertsuptoandincluding900mminternaldiametershallcomplywiththisSeriesandanyadditionalrequirementsinAppendix5/1.Drainsconstructedusingpipesexceeding900mminternaldiameteraswellasboxandpipedculvertsshallcomplywithSeries2500.UnlessotherwisedescribedinAppendix5/1onlyonetypeofpipeshallbeusedwithinanyindividualdrainorserviceductbetweenconsecutivechambers.TheContractorshallensurethatplasticspipesarenotsubjecttodeteriorationduetosunlightduringtheperiodbetweenmanufactureandinstallationintheground.

Pipes for drainage

3 PipesfordrainageshallbeselectedfromthealternativesinTable5/1andshallcomplywiththestandardsandparticularrequirementstherein.TheContractorshallshowthatthepipesheselectshavehydraulicflowcapacityequaltothatadoptedinthehydraulicdesignofthesystemasdescribedinAppendix5/1.PipesandfittingsotherthanthoseincludedinTable5/1shallbepermittedprovidedthattheyholdacurrentBritishBoardofAgrémentRoadsandBridgesCertificate(orequivalent)statingthattheyareasuitablealternativefortheusagespecifiedinTable5/1.Oncompletionofthewholeofthedrainageworks,theContractorshallprovidetheOverseeingOrganisationwithascheduleshowingdetailsofallpipetypesused,includingquality,jointsandnameofmanufacturer.

corrugated Steel Pipes

4 Corrugatedsteelpipesshallbemanufacturedfromeither:

(i) boltedsegmentalplatepipescomplyingwithsub-Clause6ofthisClauseandhavingplatethicknessesasdescribedinAppendix5/1;or

(ii) (05/06)galvanizedsteelsheetsuitableforlockseamfabricationcomplyingwithBSEN10327gradeDX51D+Z600,oraluminiumcoatedsteelsheetcomplyingwithAASHTOspecificationM274-87(2004).

Corrugatedsteelpipescomplyingwith(ii)aboveshallbemanufacturedfromsteelofminimumthickness1.25mmunlessotherwisedescribedinAppendix5/1.

5 (11/03)WheredescribedinAppendix5/1corrugatedsteelpipesshallbeprovidedwithadditionalprotectionofhotappliedbitumencomplyingwithAASHTOspecificationM190-95(2000),oranequivalentcoatingsystem.

6 Boltedsegmentalplatepipesshallmeetthefollowi1ngrequirements:

(i) (11/03)SteelfortheplatesshallcomplywithBS1449:Part1.1,Grade3orGrade4,ConditionHR.

(ii) Afterforming,thedepthofthecorrugationsshallbewithinatoleranceof±6%andthepitchofthecorrugationswithinatoleranceof±4%ofthenominaldimensions.Platesshallhaveaminimumlipof45mmbeyondeachendcrest.Cutedgesshallbefreefromnotches,gouges,rustorburrs.

(iii) (11/06)BoltsandnutsforconnectingplatesshallcomplywithBSENISO4014,BSEN4017andBSENISO4032,forBSENISO898-1and‘BSEN20898-2,ISO898-2’propertyclass8.8,nominalsizeM20;orwithBS4395:Part2,nominalsizeM20;orwithBSENISO898-1and‘BSEN20898-2,ISO898-2’propertyclass10.9.

(iv) Whenalltheplateshavebeenassembled,thenutsshallbetightenedagainstadomedwasher.Thetighteningshallberepeatedifnecessarytoachievethetorquerecommendedbythemanufacturer.



(v) SteelplateshallbegalvanizedincompliancewithClause1909.Platesshallbegalvanizedafterformingthecorrugationsandcompletingallnecessarycutting,punchinganddrilling.Unitsinwhichthezinccoatinghasbeenburnedbyweldingorotherwisedamagedinfabrication,transportorhandlingatSiteshallbemadegoodincompliancewithClauses1907and1908.BoltsandnutsshallbegalvanizedincompliancewithClause1909.

Amendment-May2006 3

taBLE 5/1:(05/05)Pipes for drainage

Material usage Standard Particular RequirementsVitrifiedclay Fouldrains BS65or

BSEN295“Normal”pipesasdefinedinBS65

Surfacewaterdrains BS65orBSEN295

“Normal”or“surfacewater”pipesasdefinedinBS65

Filterdrains BS65BSEN295

Unperforated,notexceeding2.0minlengthwithspigotandsocketopenjointsORPerforatedwithflexiblemechanicaljoints

Concrete(WithPortlandcementorsulfate-resistingcementwhenrequiredinAppendix5/1.Supersulfatedcementshallnotbeused)

Foul&surfacewaterdrainsnotexceeding900mminternaldiameter

BS5911-1andBSEN1916(Ordinaryreinforcedorunreinforced)BS5911-5

Surfacewaterdrainsnotexceeding900mminternaldiameter

BS5911-110 Forusewithjointscomplyingwithsub-Clause504.4

Filterdrains BS5911-114(Porouswithogeeorrebatedjoints)BS5911-110 Unperforatednotexceeding2minlength

withopenjointsorcastellatedrebatedjointswiththetotalslotareabetweencastellationsbeingatleast1000mm²permetrelengthofpipeORPerforatedwithcircularholesnotgreaterthan10mmnorlessthan3mmindiameter

Glassreinforcedplastics(GRP) Foul&surfacewaterdrains BS5480 ClasstobeasspecifiedinAppendix5/1Iron Foul&surfacewaterdrains BS437(Castiron)

BSEN598(Ductileiron)


taBLE 5/1: (11/06) Pipes for drainage (continued)

Material usage Standard Particular RequirementsThermoplasticssolidwallpipesandfittingsnotexceeding900mmdiameterUnplasticisedpolyvinyl-chloride(PVC-U)

Polypropylene(PP)

Polyethylene(PE)

Foul&surfacewaterdrains

BS4660orBS5481orBSEN1401(PVC-U)BSEN1852-1(PP)BSEN12666-1(PE)

SeetheUKnationalforwardtotherelevantBSEN.Thegradeappropriateforusewithoutstructuralcalculationsshallbeusedi.e.SN8forPP&PEandSN4(SDR41)forPVC-U

Filterdrains BS4660orBS5481orBSEN1401(PVC-U)

BSEN1852-1(PP)

BSEN12666-1(PE)

Perforatedwithnotlessthan1000mm²ofholespermetrelengthofpipe.Theperforationsshallnotreducethepipestiffnessbymorethan5%.Circularperforationsnotgreaterthan10mmnorlessthan3mmindiameterorrectangularslotsnotgreaterthan4mmnorlessthan0.6mminwidth

Thermoplasticsstructuredwallpipeandfittingsnotexceeding900mmdiameter

Surfacewaterdrains Clause518 Unperforatedwithwatertightjointsandwithapipestiffnessclass,creepratioandimpactresistanceasdescribedinAppendix5/1

Filterdrains Clause518 Perforatedwithnotlessthan1000mm2ofholespermetrelengthofpipe.Theperforationsshallnotreducethepiperingstiffnessbymorethan5%.Circularperforationsnotgreaterthan10mmnorlessthan3mmindiameterorrectangularslotsnotgreaterthan4mmnorlessthan0.6mminwidth

Subsoilfielddrains BS4962orClause518

Corrugatedsteel Surfacewaterdrains,filterdrainsnotexceeding900mminternaldiameter

AASHTOspecificationM36M-01exceptasotherwiserequiredinsub-Clauses501.4,5and6

Alldrainsexceeding900mminternaldiametershallcomplywithSeries2500.

Pipes for Service ducts


7 (11/09)Pipesforserviceducts,excludingthoseinuseinmotorwaycommunicationsinstallations,shallbeselectedfromthealternativesinTable5/2andshallcomplywiththestandardsandparticularrequirementstherein.PipesforuseinmotorwaycommunicationsinstallationsshallcomplywithSeries1500.PipesforotherserviceductsinstalledusingtrenchlessmethodsshallconformtoSeries8000(MCHW5.8.2).Pipesforserviceductsshallhaveasmoothinternalborewithoutanysharpedgestotheendsofpipes.TheyshallcomplywithanyadditionalrequirementsdescribedinAppendix5/2,andbeof100mminternaldiameterunlessotherwisedescribedtherein.Theiralignmentshallbetestedinaccordancewithsub-Clause509.9.TheuseofpipesandfittingsotherthanthoseincludedinTable5/2shallbepermittedprovidedthattheyholda

currentBritishBoardofAgrémentRoadsandBridgesCertificate(orequivalent)statingthattheyareasuitablealternativetothoselistedinTable5/2.

8 Eachductshallbefittedwithapigmented,strandedpolypropyleneorequivalentrot-proofmaterialdrawropeof5kNbreakingloadandhavingadesignlifeofnotlessthan20years,theendsofwhichshallbeeithermadefasttomarkerblocksasshownonHCDDrawingNumberI1orsecuredinsidechambers.Theendsofaductshallbeeithersealedbyremovablestoppersimmediatelyithasbeenlaid,orterminatedinchambersofthetypespecifiedinAppendix5/2.

Volume 1Specification for Highway Works

Series 500Drainage and Service Ducts

5

TABLE 5/2: (11/06) Pipes for Ducts

Material Standard Particular Requirements

Vitrified clay BS 65 or Plain-ended, self-aligning flexible sleeve jointed with internal endsBS EN 295 radiused to 3 mm minimum

Iron BS EN 598(Ductile iron)

Glass reinforced plastics BS 5480 Class to be as specified in Appendix 5/2

Thermoplastics solid wall BS 4660 or When pipes BS 3506 (Class C) are used, joints shall comply withBS 5481 or BS EN 1452-1 to 5 as appropriate

Unplasticised polyvinyl-chloride BS 3506 (Class C) or(PVC-U) BS EN 1401,

BS EN 1452-1 to 5 asappropriate class PN10.

Polypropylene (PP) BS EN 1852-1 (PP)

Polyethylene (PE) BS EN 12666-1 (PE)

Thermoplastics single wall BS EN 50086-2-4 Ducts to BS EN 50086-2-4 shall be classified as normal duty,corrugated have a degree of protection against ingress of foreign objects(Restricted to ducts buried a classification rating of 3 or 4 and a degree of protection againstminimum of 600 mm below the ingress of water classification rating of 7. Appendix 5/2 shall statesurface) the resistance to bending requirements.

Thermoplastics structured wall BS EN 50086-2-4 and Ducts to BS EN 50086-2-4 shall be classified as normal duty,Clause 518 have a degree of protection against ingress of foreign objects

classification rating of 3 or 4 and a degree of protection againstingress of water classification rating of 7. Appendix 5/2 shall statethe resistance to bending requirements.

Pipes for use in motorway communications installations shall comply with Series 1500

502 Excavation for Pipes and Chambers

1 Excavation shall comply with Clause 602 and withthe following:

(i) (05/04) soft spots existing below the bottomof an excavation shall be removed and theresulting voids backfilled with Type 1unbound mixture for subbase complyingwith Clause 803 or pipe bedding materialcomplying with Clause 503, both wellcompacted, or ST1 concrete in compliance toClause 2602;

(ii) any additional excavation below the bottomof an excavation that is required because theContractor has allowed the bottom tobecome soft or otherwise unacceptable forthe construction of the pipeline or chambersshall be made good as described insub-Clause 1(i) of this Clause;

(iii) any excavation greater than the net volumerequired for the Permanent Works below thelevel of any pipe surround shall be madegood as described in (i) above.

2 Unless otherwise described in Appendix 5/1, allpipes in or under new embankments shall be laid onlywhen the embankment has been formed and compactedto formation level under paved areas, to finishedearthworks level in other areas, or to a level which willgive a minimum cover of 1.2 m to the pipes, whicheveris the lowest.

503 (11/05) Bedding, Laying and Surroundingof Pipes

1 Immediately following the excavation of thetrench, the pipes shall be laid and jointed on the pipebed. Pipes shall be laid so that each one is in contactwith the bed throughout the length of its barrel. Thepipes shall be laid at the level and gradients shown onthe Drawings and schedules. The deviation in levelfrom that specified at any point shall not exceed 20 mmand in addition the algebraic difference of the deviationin level at any two points on each pipe shall not exceed30 mm. In the case of socketed or sleeve jointed pipesthe bed shall be cut away and removed at each socket orsleeve to give a clearance of at least 50 mm, or 100 mmfor trenches in material designated as Hard Material, so

Amendment - November 2006



6

that the socket or sleeve does not bear on the bed. Pipesshall be laid on setting blocks only where a concretebed or cradle is used.

Pipes and fittings shall be examined for damage and thejoint surfaces and components shall be cleanedimmediately before laying. Measures shall be taken toprevent soil or other material from entering pipes, andto anchor each pipe to prevent movement before thework is complete.

2 Pipes complying with BS 4962 : 1989 which arecorrugated coilable perforated pipes shall, unlessotherwise permitted in Appendix 5/1, be laid only byautomatic single pass drain laying machines.

3 (11/06) Drainage pipe and bedding combinationsshall be selected from the alternatives described inAppendix 5/1. The granular material shall consist ofnatural and/or recycled coarse aggregate or recycledconcrete aggregate complying with BS EN 13242.Where recycled coarse aggregate or recycled concreteaggregate is used in this Clause, it shall have beentested in accordance with Clause 710 and shall notcontain more than 1% other materials (Class X). Pipebedding, haunching and surrounding material shall beas shown on HCD Drawing Numbers F1 and F2, andshall comply with the following:

(i) (05/04) For pipes on beds shown on HCDDrawing Number F1 as Types B, F and S theaggregate shall have:

(a) (05/04) geometrical requirements inaccordance with Table 5/3;

(b) (05/04) a resistance to fragmentation inCategory LA50 in accordance withBS EN 13242, clause 5.2 and Table 9;

(c) (11/07) a water-soluble sulfate content ofless than 0.38% of sulfate (as SO3) whentested in accordance withBS EN 1744-1, clause 10;

(d) (05/04) all other requirements inCategory NR.

(ii) (05/04) For pipes on beds shown on HCDDrawing Number F1 as Types N and T theaggregate shall comply with the geometricalrequirements of either Table 5/3 or withTable 5/4, and with the fragmentation, water-soluble sulfate content and otherrequirements of (i) above.

TABLE 5/3: (05/04) BS EN 13242, Coarse aggregatefor pipe bedding, haunching and surroundingmaterial

BS EN 13242, Coarse aggregate (clause 4.3.2)

Category for general grading GC80-20requirements

Category for tolerances at GTNR (no requirements)mid-size sieves

Category for maximum values of Gravel - f1.5fines content Crushed rock, recycled

aggregate - f4

Aggregate size, mm Nominal pipe diameter, mm

Graded Single sized

Not exceeding 140 - 4/10

Exceeding 140 but not 2/14 or 4/20 4/10, 6/10 orexceeding 400 10/20

Exceeding 400 2/14, 4/20 4/10, 6/14,or 4/40 10/20 or 20/40

TABLE 5/4: (05/04) BS EN 13242, Fine and all-inaggregated for pipe bedding, haunching andsurrounding material

BS EN 13242, Fine and all-in aggregate (clause 4.3.3)

Fine All-in

Category for general grading Category Category GA80requirements GF80

Category for tolerances on GTFNR GTANRmanufacturer’s declared (no requirement) (no requirement)typical grading

Category for maximum Gravel - f3values of fines content Crushed rock, recycled

aggregate - f11

Aggregate size, mmNominal pipe diameter, mm

Fine All-in

Not exceeding 140 0/10

Exceeding 140 but not 0/1, 0/2, 0/4 0/10 or 0/20exceeding 400 or 0/6

Exceeding 400 0/10, 0/20 or0/40

(iii) (11/03) For pipes on beds shown on HCDDrawing Number F1 as Types A and Zconcrete shall be ST4 and ST2, incompliance to Clause 2602, respectively.Backfilling shall not be carried out until afterthe concrete has cured.

Amendment - November 2007


(iv) Exceptforfilterdrainsafurthersurroundabovethebed,haunchandsurrounddescribedaboveshallbeprovidedtoaheightof300mmabovethetopofthepipeconsistingofClass8lowertrenchfillmaterialasdescribedinTable6/1andincompliancewithSeries600.

(v) UnlessotherwisedescribedinAppendix5/1thematerialsusedforthebedding,haunchingandsurroundingoffilterdrainsshallcomplywiththeappropriatebedding,haunchingandsurroundingmaterialsspecifiedinsub-Clauses503.3.(i)to503.3.(iv)andwiththerequirementsforbackfillingspecifiedinsub-Clause505.3.

4 (05/04)Materialforbedding,haunchingandsurroundingpipesshallnotbedepositedwithin500mm,oranyotherdistancesdescribedinAppendix5/1,ofconcrete,cementboundmaterials,othercementitiousmaterialsorstabilisedcappingformingpartofthePermanentWorksif,whentestedinaccordancewithTRLReport447either:

(i) (11/05)thewater-solublesulfate(WS)contentexceeds1500mgofsulfate(asSO4)perlitre(TestNo.1);or

(ii) (11/09)theoxidisablesulfides(OS)contentexceeds0.5%ofsulfate(asSO4)(TestNo.2andTestNo.4);or

(iii) (11/09)the2:1watertosoilextractpreparedforthedeterminationofwater-solublesulfatein(i)hasapHvalueoflessthan7.2,whentestedusingtheelectrometricmethodofpHdeterminationinaccordancewithBS1377-3.

(11/09)AtleastfivesamplesofeachmaterialshallbetestedforWS,OSandpHvalue.Themeanofthehighesttwovaluesshallbeusedforcomparisonwiththelimitingvalues.Thisalsoappliesifsixtonineresultsareavailable.Iftenormoreresultsareavailable,themeanofthehighest20%oftheresultsshallbeusedforcomparisonwiththelimitingvalues.

5 (11/07)Materialforbedding,haunchingandsurroundingpipesshallnotbedepositedwithin500mm,oranyotherdistancesdescribedinAppendix5/1,ofmetallicstructuralelementsformingpartofthePermanentWorksif,whentestedinaccordancewithTRLReport447either:


(ii) theoxidisablesulfides(OS)contentexceeds0.06%ofsulfate(asSO4)(TestNo.2andTestNo.4).

(11/05)AtleastfivesamplesofeachmaterialshallbetestedforWSandOS.Themeanofthehighesttwovaluesshallbeusedforcomparisonwiththelimitingvalues.Thisalsoappliesifsixtonineresultsareavailable.Iftenormoreresultsareavailable,themeanofthehighest20%oftheresultsshallbeusedforcomparisonwiththelimitingvalues.

(11/07)Therequirementsin(i)and(ii)aboveshallnotapplytometallicitemsprotectedbyconcreteandancillarymetallicitemssuchasthetopsofchambersandgullies.6 (05/04)ExceptwherethepipelineistobetestedincompliancewithClause509beforebackfilling,thecompletionofthebedding,haunchingandsurroundingofthepipesistobecarriedoutimmediatelyafterjointing.Thebed,haunchandsurroundshallbebroughtupequallyonbothsidesofthepipeensuringthatitisincontactwiththeundersideofthepipebarrelandbecarefullycompactedinlayersnotexceeding150mmthicknessensuringfullcompactionnexttothetrenchwalls.Pipesshallbemaintainedtolineandlevelduringthebedding,haunchingandsurroundingoperations.Wherepipelinesaretobetestedbeforebeingcoveredthebeddinghaunchingandsurroundingmaterialshallonlybebroughtupsufficientlytosupportthepipelineandthejointsshallbeleftexposeduntilthetestiscompletedsatisfactorily.7 (05/04)DuctconstructionshallcomplywiththerequirementsofAppendix5/2.

504 Jointing of Pipes

1 Rigidjointsshallmeanjointsmadesolidbycaulkingthesockets,orboltingtogetherflangesintegralwiththepipes.Flexiblejointsshallmeanjointsmadewithdeformableringsorgasketsheldbetweenpipespigotsandsockets,sleevesorcollars.

2 Jointsinsurfacewaterdrainsshallbewatertightcomplyingwithsub-Clause3ofthisClauseorpartlywatertightcomplyingwithsub-Clause4ofthisClauseasdescribedinAppendix5/1.Fouldrainsshallhavewatertightjoints.Filterdrainsshallhavejointscomplyingwithsub-Clause6ofthisClause.DuctsneednothavewatertightjointsunlessotherwisedescribedinAppendix5/2.

3 (05/01)WatertightjointsshallcomplywiththeappropriateBritishStandards,themanufacturer’sinstructionsandthefollowing:



(i) RigidjointsshallbeusedonlywherepermittedinAppendix5/1.Spigotsandsocketsofrigidjointsmaybecaulkedwithtarredropeyarnorequivalentandthesocketcompletelyfilledwithmortardesignation(i)complyingwithClause2404,excludinglime;afilletofmortarbeingworkedaroundthesocketextendingforalengthofnotlessthan50mmfromthefaceofthesocket.Ironpipeswithopensocketsshallhaverigidjointscaulkedwithleadwoolorequivalent.

(ii) JointsinPVC-Upipesshallnotbemadewithplasticsolvent.

(iii) FlexiblemechanicaljointsmaybeusedwithsurfacewaterpipescomplyingwithBS65.

(iv) (11/03)JointsforcastironpipestoBS437shallcomplywithBSEN877.

(v) JointsinthermoplasticsstructuredwallpipeshallcomplywithClause518.

4 (05/01)Partlywatertightjointsforsurfacewaterdrainsshallbetestedinaccordancewithsub-Clause509.7andshallbeBritishStandardjointsornon-BritishStandardjoints.Pushfitjointsshallhavearegistertoensurethatthepipeisfullypushedintothejoint.

Corrugatedsteelpipesoflockseamfabrication,notexceeding900mminternaldiameter,shallbejoinedinaccordancewiththemanufacturer’sinstructions.Boltedsegmentalplatepipearchesorcircularpipes,notexceeding900mminternaldiameter,shallbejoinedinaccordancewithsub-Clause501.6(iv)andthemanufacturer’sinstructions.

5 Whereaconcretebed,cradle,archorsurroundisusedwithrigidpipeshavingflexiblejoints,jointfillerboardcomplyingwithClause1015shallbeplacedincontactwiththeendofthesocketatapipejointandshallextendthroughthefullthicknessoftheconcreteincontactwiththepipe.Suchjointsintheconcretebed,haunchorsurroundshallbeatintervalsnotexceeding5metresexceptwherethespacingofjointsinthepipeexceeds5metreswhentheyshallbeateachpipejoint.

6 (05/01)JointsinpipesforfilterdrainsshallcomplywiththeappropriateBritishStandardandwiththefollowing:

(i) Non-porousandunperforatedconcreteandclaypipeswithspigotandsocket,rebatedorogeejointsshallbelaidwithunsealedjointsandwithagapof10mmbetweentheendofthepipeandtheinnerendofthesocketorrebate.Thepipesshallbesupportedwithtarredropeyarnorequivalentflexiblejointingmaterialwithinthesocketsoverthe

lowerthirdofthecircumferencesothattherearenoverticalstepsbetweenonepipeandanother.SuchpipesshallonlybeusedwithTypeBfiltermaterialasdescribedinClause505.

(ii) Theendsofperforated,castellatedorporousconcretepipeswithrebatedjointsandperforatedclaywarepipeswithrebatedorwithflexiblesleevejointsshallbepushedtightlytogether.Thewidthofslotsmeasuredalongthelengthofthepipelineformedbyjointingcastellatedpipesshallnotexceed10mm.

(iii) Perforatedorslottedthermoplasticspipeswithspigotsandsocketsorsleevesmaybedry-jointedorjointedasdescribedinsub-Clauses3and4ofthisClause.

(iv) Otherperforatedpipesshallbejointedasunperforatedpipesofthesamematerial.

7 JointsinpipesforserviceductsshallcomplywiththeappropriateBritishStandardandwiththefollowing:

(i) Pipesforductsshallbejointedsothatnosilt,grit,groutorconcretesurroundisabletoentertheduct.Pipeswithpush-fitjointsshallhavearegistertoensurethatthepipeisfullypushedintothejoint.

(ii) (05/05)JointsinpipestoBS3506shallcomplywithBSEN1452-1to5asappropriate.

505 Backfilling of trenches and Filter drains

1 Backfillingshallbeundertakenimmediatelyaftertherequiredoperationsprecedingithavebeencompleted.

2 ExceptwhereotherwisedescribedinAppendix5/1,trenchesotherthanfilterdraintrenchesshallbebackfilledabovethepipesurroundmaterialdescribedinClause503,withClass1,2,or3generalfillmaterialcomplyingwithSeries600.

3 (11/06)FilterdrainsshallbebackfilledasdescribedinAppendix5/1withTypeA,TypeBorTypeCfiltermaterialwhichshallconsistofnaturalorrecycledcoarseaggregateorrecycledconcreteaggregatecomplyingwithBSEN13242andthefollowing:

(i) forTypeAandC,gradingrequirementsforunboundmixturesinaccordancewithTable5/5andBSEN13285;

(ii) forTypeB,geometricalrequirementsinaccordancewithTable5/5andBSEN13242;



(iii) aresistancetofragmentationinCategoryLA50inaccordancewithBSEN13242,clause5.2andTable9;

(iv) (11/07)awater-solublesulfatecontentoflessthan0.38%ofsulfate(asSO3)whentestedinaccordancewithBSEN1744-1,clause10;

(v) allotherrequirementsinCategoryNR;


(vi) benon-plasticwhentestedinaccordancewithBS1377:Part2.

WhererecycledcoarseaggregateorrecycledconcreteaggregateisusedinaccordancewiththisClause,itshallhavebeentestedinaccordancewithClause710andshallnotcontainmorethan1%othermaterials(ClassX).

table 5/5:(11/05)grading and geometrical requirements for filter drain material

type a type B type cStandard BSEN13285 BSEN13242 BSEN13285Size,mm 0/20 20/40

AsdescribedinAppendix5/1

Gradingandoversizecategories GF(withanadditionalsieve)

GC80-20

Oversizecategory OC80 -Categoryfortolerancesatmid-sizesieves - GTNR

(norequirement)Categoryformaximumfines UF3 fNR

(norequirement)Summarygradingrequirements

Sievesize,mm Percentagebymasspassing80 - 100

AsdescribedinAppendix5/1

63 - 98-10040 100 80-9920 80-99 0-2010 50-90 0-54 30-75 -2 15-60 -

0.500 0-35 -0.125 0-4 -0.063 0-3 -

%insizefraction4/10 5-35 -2/4 5-35 -

Filtermaterials,whentestedinaccordancewithsub-Clause509.8shallhavepermeabilityrequirementsasdescribedinAppendix5/1.

WhenTypeAmaterialisusedwithpipesotherthanporouspipesatleast15%ofthematerialshallbelargerthanthediameterofholeorlargerthan1.2timesthewidthofslotinthepipe.

4 (11/07)Materialforbackfillingtrenchesandfilterdrainsshallnotbedepositedwithin500mm,orany

otherdistancesdescribedinAppendix5/1,ofconcrete,boundmaterials,othercementitiousmaterialsorstabilisedcappingformingpartofthePermanentWorksif,whentestedinaccordancewithTRLReport447either:



(ii) (11/09)theoxidisablesulfides(OS)contentexceeds0.5%ofsulfate(asSO4)(TestNo.2andTestNo.4);or

(iii) (11/09)the2:1watertosoilextractpreparedforthedeterminationofwater-solublesulfatein(i)hasapHvalueoflessthan7.2,whentestedusingtheelectrometricmethodofpHdeterminationinaccordancewithBS1377-3.

(11/09)AtleastfivesamplesofeachmaterialshallbetestedforWS,OSandpHvalue.Themeanofthehighesttwovaluesshallbeusedforcomparisonwiththelimitingvalues.Thisalsoappliesifsixtonineresultsareavailable.Iftenormoreresultsareavailable,themeanofthehighest20%oftheresultsshallbeusedforcomparisonwiththelimitingvalues.

5 (11/07)Materialforbackfillingtrenchesandfilterdrainsshallnotbedepositedwithin500mm,oranyotherdistancesdescribedinAppendix5/1,ofmetallicstructuralelementsformingpartofthePermanentWorksif,whentestedinaccordancewithTRLReport447either:


(ii) theoxidisablesulfides(OS)contentexceeds0.06%ofsulfate(asSO4)(TestNo.2andTestNo.4).

(11/05)AtleastfivesamplesofeachmaterialshallbetestedforWSandOS.Themeanofthehighesttwovaluesshallbeusedforcomparisonwiththelimitingvalues.Thisalsoappliesifsixtonineresultsareavailable.Iftenormoreresultsareavailable,themeanofthehighest20%oftheresultsshallbeusedforcomparisonwiththelimitingvalues.(11/07)Therequirementsin(i)and(ii)aboveshallnotapplytometallicstructuralelementsprotectedbyconcreteandancilliaryitemssuchasthetopsofchambersandgullies.6 (05/04)BackfillingshallbedepositedandcompactedincompliancewithClause612.Filtermaterialforfilterdrainsshallbedepositedinlayersnotexceeding225mmloosedepth;eachlayerbeingcompactedincompliancewithTable6/4Method3.7 (05/04)Materialshallbedepositedinevenlayersandshallnotbeheapedinthetrenchbeforebeingspread.Spreadingandcompactionshallbecarriedoutevenlywithoutdislodging,distortingordamagingthepipe.Powerrammersshallnotbeusedwithin300mmofanypartofthepipeorjoint.8 (05/04)Exceptincarriageways,otherpavedareasandlocationsdescribedinAppendix5/1,backfilloftrenchesshallbebroughtuptogroundlevel.Where

topsoilisatthesurfaceonthelineofthetrenchtheuppersectionofthebackfillshallbetopsoilofthethicknessdescribedinAppendix6/8,orofthesamethicknessandqualityoftopsoilasthesurroundinggroundwherenothicknessisspecified.Fortrenchesincarriagewaysorotherpavedareasthebackfillshallbebroughtuptoformationlevel,orsub-formationlevelwherecappingisrequired,unlessalowerlevelisdescribedinAppendix5/1.SheetingandotherexcavationsupportsshallberemovedasthefillingproceedsunlessotherwisedescribedinAppendix6/3.9 (05/04)ThepositionofserviceductsshallbemarkedwhenthetrenchesarebackfilledandpermanentmarkerblocksandlocationpostsprovidedasdescribedinAppendix5/2.

506 connecting to Existing drains chambers and channels

1 WheredescribedinAppendix5/1,existingdrainsshallbeextended,connectedandjointedtonewdrains,chambersorchannels.AllsuchconnectionsshallbemadeduringtheconstructionofthenewdrainorotherworkandtheirpositionsrecordedbytheContractorwhoshallhandtotheOverseeingOrganisationacopyoftherecordoftheconnectionsmadethepreviousday.Wherepipeconnectionsaremadetoexistingbrickconcreteorstonedrains,chambersorchannels,thepipesshallbewellandtightlybuiltintotheconcrete,brickormasonryworkandbesoplacedastodischargeatananglenotgreaterthan60°tothedirectionofflowofthedrainorchannelandwiththeendofthepipecarefullycuttothenecessaryangle.Wheretheconnectionsarebetweenpipedrains,specialconnectingpipesshallbelaidandjointedasdescribedinAppendix5/1.

2 Beforeenteringorbreakingintoanexistingsewerordrain,theContractorshallgivenoticeofhisintentiontodosototheauthorityresponsibleforthepipelinetowhichtheconnectionistobemade.

3 (11/06)Existingdrainsnolongerrequiredshall,asrequiredbyAppendix5/1,besealedwithST2concrete,incompliancetoClause2602,orremovedandreplacedwithgeneralfillmaterialcomplyingwithClause601andTable6/1andcompactedincompliancewithClause612,orgroutedwitha1:10,cement:pfamix.Thegroutshallusetheminimumquantityofwatertoensurethefluiditynecessarytorenderitcapableofbeingpumpedtotheendsofthepipe.Itshallbeusedwithinonehourofmixingbutwhenthemixcontainsaretardingadmixturethistimemaybeextendedinaccordancewiththemanufacturer’sinstructions.ThecementshallcomplywithBS197-1andthepulverised-fuelash(pfa)withBS3892:Part2,finenesstoZoneBandsulfatecontentnotexceeding1.5%.



507 (05/01) chambers

1 (11/03)Chambers,otherthanthoseusedinmotorwaycommunicationsinstallations,shallincludemanholes,catchpits,inspectionchambers,drawpitsandwalledsoakaways.ChambersshallbeofthetypespecifiedinAppendix5/1,constructedinaccordancewithHCDDrawingNumbersF3toF12andF25toF27asappropriatetothattype.ChambersforuseinmotorwaycommunicationsinstallationsshallcomplywithSeries1500.AllSTconcretereferredtointhisClauseshallcomplywithClause2602,unlessotherwisedescribedinAppendix5/1.

2 (11/03)FoundationstochambersshallbeofST4concrete.Channelsforchambersshallbeformedandfinishedsmoothinthefoundationconcreteorconstructedofpreformedhalfcirclechannels,withsidesbenchedinST4concrete,ormortardesignation(i)complyingwithClause2404excludinglime.Alternativelyforinspectionchambersnotexceeding1.3metresindepthtoinvert,completeplasticsunitsorotherunitsinequivalentmaterialsurroundedby150mmofST4concretemaybeused.

3 BrickworkshallcomplywithSeries2400andbebuiltwithmortardesignation(i)inEnglishbond.ThejointsofbrickworkwhereexposedshallbefinishedasspecifiedforunpointedjointsinClause2412.Theendsofallpipesshallbeneatlybuiltintothebrickworkandfinishedflushwithmortardesignation(i).

4 (11/04)PrecastconcretechambersshallcomplywithBS5911-3andBSEN1917andtheparticularrequirementsdescribedinAppendix5/1.Castin-situconcretechambersshallbeconstructedofST4concretecomplyingwithClause2602andtheparticularrequirementsdescribedinAppendix5/1.

5 (11/04)CorrugatedgalvanizedsteelchambersshallcomplywithClause501withinsituST4concreteinvertsandprecastconcretecoverslabscomplyingwithBS5911-3andBSEN1917andtheparticularrequirementsdescribedinAppendix5/1.TheyshallbesurroundedwithwellgradedgranularmaterialClass6MasdescribedinTable6/1compactedinaccordancewithClause612.

6 (11/04)Wherethedepthofinvertofchambers,excludinginspectionchambers,exceeds900mmbelowthefinishedsurfaceofthecarriagewayortheadjacentground,manholestepscomplyingwithBSEN13101shallbebuiltinaccordancewithrelevantSeriesF-HCDDrawings.Steelworkusedforladders,handholdsandotherfittingsshallcomplywithBS970:Part1andbegalvanizedincompliancewithClause1909afterfabrication.ThreadedcomponentsshallbegalvanizedincompliancewithClause1909.

7 (11/03)Excavationaroundchambers,exceptthosedescribedinsub-Clause5ofthisClause,shallbebackfilledwithgeneralfillmaterialasdescribedinTable6/1andcompactedincompliancewithClause612.Wheremechanicalcompactionisimpracticable,theexcavationshallbebackfilledwithST2concrete.Wherethereareprecastconcreteaccessshaftstoprecastconcretechambers,theshaftsshallbesurroundedbyaminimumthicknessof150mmofST4concrete,andtheremainingexcavationbackfilledwithgeneralfillmaterialasdescribedinTable6/1compactedincompliancewithClause612.

8 ChambersforfouldrainsshallbetestedforwatertightnessasandwhererequiredinAppendix5/1.

9 (11/09)Chambercovers,gratingsandframesshallbeasdescribedinAppendix5/1andshallcomplywithBSEN124andsub-Clauses10and15ofthisClause.Thecovershallbeofsuitablematerial,designandconstructiontoachieveanin-serviceskid/slipresistancepotentialsuitablefortheconditionsofuse.ThisshallbedeterminedbytheacceleratedpolishtestmethoddescribedinBS9124.ThePSRVshallbeasstatedinAppendix5/1.

10 ClassD400unitsandaboveshallincorporateapermanentnon-rockfeatureeithertriangularpointsuspensionormachinedfaces.

11 (11/03)Boltssuppliedforlooselycouplingseparatesectionsofcoversandgratingsshallbesteelhexagonheaded,complyingwiththerequirementofBSENISO4016,BSENISO4018andBSENISO4034andbegalvanizedincompliancewithClause1909.TheyshallnotbelessthansizeM16completewithhexagonnutandshallbeprovidedwithmeanstopreventunduetighteningofunitsections.

12 UnlessotherwisespecifiedinAppendix5/1,allcovers,gratingsandframesshallbesuppliedinafinecast(uncoated)condition.WhereacoatingisspecifiedinAppendix5/1,thecoatingshallonlybeappliedwhenthesurfacesofthecastingareclean,freefromrustanddry.

13 RequirementsforspecialdutycoversforuseincarriagewaysshallbeasdescribedinAppendix5/1.

14 GratingsforcatchpitchambersshallhaveaminimumwaterwayareaasdescribedinAppendix5/1.

15 TwosetsofliftingkeysshallbedeliveredtotheOverseeingOrganisationforeachtypeofcoversupplied.Atleasttwokeyways,asdetailedonHCDDrawingNo.F17,shallbeprovidedineachcompletecover,oneineachsegmentforsegmentalcovers.Arecessforaprisingbarshallbeincorporatedinmanholecoversunlessothermeansoflooseningthecoverfromtheframeareprovided.



16 Framesforchambercoversandgratingsshallbesetincementmortardesignation(i)complyingwithClause2404oraproprietaryquicksettingmortarofequivalentstrength.

17 Forallpipelinesexceptthoseconstructedwithcorrugatedpipesthenearestjointtoanychambershallbenotmorethan500mmfromtheinnerfaceofthewallandshallnotberestrictedbyanyconcrete.Betweenthisandthenextjoint,thelengthofthearticulatedpipeshallbeinaccordancewithTable5/6.

taBLE 5/6: Length of articulated Pipe

nominal Pipe diameter (mm) Length of Pipe (mm)450andless 500to750Greaterthan450 750to1000

18 Wheretheadjustmentorreplacementofexistingframesandcoversorgratingsisrequired,theunitsshallbetakenupandre-fixedorremovedandreplacedwithnewunitscomplyingwithsub-Clauses9to15ofthisClause,orasdescribedinAppendix5/1.Ontakinguporremovaloftheunit,anyconcreteormortarbeddingshallbebrokenoutandthesurfaceprepared.Whereexistingframesandcoversorgratingsaretobeadjusted,theContractorshalltakeuptheunitandcleanitforre-use.Theadjustedorreplacedunitsshallbelaidonamortarbedcomplyingwithsub-Clause16ofthisClause.Thefinishedthicknessofthemortarbedshallbebetween10mmand25mm.WhererequiredinAppendix5/1,coversandgratingsshallbebeddedusingaproprietaryquicksettinghighstrengthmortar.DetailsofsuchmortarshallbetotheapprovaloftheOverseeingOrganisation.UnlessotherwisedescribedinAppendix5/1,adjustedorreplacedframesandcoversorgratingsshallbesetflushwiththenewsurface.Anyadditionaladjustmentsshallbebymodifyingthebrickworkincompliancewithsub-Clause507.3orbyusingaframeofasuitabledepth.Oncompletionoftheworks,eachcovershallbeliftedandtheframeandseatingcleaned.

#508 gullies and Pipe Junctions

1 (05/06)Gulliesshallbetrapped,untrappedorsumplessasdescribedinAppendix5/1andbeinaccordancewithHCDDrawingNumbersF13andF14.AllSTconcretereferredtointhisClauseshallcomplywithClause2602unlessotherwisedescribedinAppendix5/1.

2 Gulliesshallbeconstructedsothatnopartofthespoutortraphasacross-sectionalarealessthan2/3rd

thatoftheoutlet.Thedepthofwatersealintrappedgulliesshallbenotlessthan50mm.

3 (05/05)PrecastconcretegulliesshallcomplywithBS5911-6andclaygullieswithBSEN295.InsituconcretegulliesshallbeasdescribedinAppendix5/1andconstructedofST4concreteof150mmminimumthickness,usingpermanentorremovableshuttering.Whereinsituconcretegulliesareformedwithpermanentshuttering,suchshutteringshallhaveacurrentBritishBoardofAgrémentRoadsandBridgesCertificate.

4 Gullygratings,kerbtypegullycoversandframesshallcomplywithBSEN124andthefollowingandshallbeoftheclassesandsizesdescribedinAppendix5/1.

5 (05/01)TheuppersurfaceofgullygratingsshallbeflatexceptwhereotherwisedescribedinAppendix5/1.Slotsingratingsorbetweengratingsandframesshallnotbeorientatedparalleltothedirectionoftrafficexceptwheretheslotsarelessthan150mmlongorlessthan20mmwide.MinimumwaterwayareasshallbeasspecifiedinAppendix5/1.UnlessotherwisespecifiedinAppendix5/1,allgratingsandframesshallbesuppliedinafinecast(uncoated)condition.WhereacoatingisspecifiedinAppendix5/1,thecoatingshallonlybeappliedwhenthesurfacesofthecastingareclean,freefromrustanddry.Framesshallbebeddedonmortarcomplyingwithsub-Clause507.16.Brickworkshallcomplywithsub-Clause507.3.

6 (05/04)Backfillingtoprecastgulliesshallbecarriedoutuptosub-formationlevelwithgeneralfillmaterialClass1,asdescribedinTable6/1compactedincompliancewithClause612.Wheremechanicalcompactionisimpracticable,thebackfillingshallbeinST2concrete.TheremainderofthebackfillingshallbeinappropriatecappingandroadpavementmaterialsexceptthatwheremechanicalcompactionofcappingorunboundmixtureforsubbaseisimpracticableST2concreteshallbeused.

7 (11/03)Gullyconnectionpipesshallbeeitherflexibleorrigidnotexceeding0.7minlengthwithflexiblejointsforadistanceof2mfromthegullyandshallbeinaccordancewithsub-Clause507.17whenenteringchambers.Junctionpipesshallbemanufacturedofthesametypeandclassofmaterialastheremainderofthepipesintherun.Junctionpipeswhicharelaidbutnotimmediatelyconnected,shallbefittedwithtemporarystoppersorsealsandthepositionofallsuchjunctionsshallbeclearlydefinedbymeansofstakesortracingwiresproperlymarkedorlabelled.SaddlesmaybeusedtoformjunctionsonlywherepermittedinAppendix5/1.Nointernalprojectionsgreaterthan5mmwillbepermitted.Saddlesforasbestoscement



andplasticspipesshallbeinstalledinaccordancewiththemanufacturer’srecommendations.Saddleswithclaypipesshallbejointedwithmortardesignation(i)complyingwithClause2404,excludinglime.SaddlesandpipesshallbesurroundedwithST2concrete.

8 (05/01)Wheretheadjustmentorreplacementofexistingframesandgratingsisrequired,theunitsshallbetakenupandre-fixedorremovedandreplacedwithnewunitscomplyingwithsub-Clauses4and5ofthisClause,orasdescribedinAppendix5/1.Ontakinguporremovaloftheunit,anyconcreteormortarbeddingshallbebrokenoutandthesurfaceprepared.Whereexistingframesandcoversorgratingsaretobeadjusted,theContractorshalltakeuptheunitandcleanitforre-use.Theadjustedorreplacedunitsshallbelaidatalevel,unlessotherwisedescribedinAppendix5/1,6mmbelowtheadjoiningroadsurfaceonamortarbedcomplyingwithsub-Clause507.16.Thefinishedthicknessofthemortarbedshallbebetween10mmand25mm.WhererequiredinAppendix5/1,coversandgratingsshallbebeddedusingaproprietaryquicksettinghighstrengthmortar.DetailsofsuchmortarshallbetotheapprovaloftheOverseeingOrganisation.Anyadditionaladjustmentshallbemadebymodifyingthebrickworkincompliancewithsub-Clause507.3orbyusingaframeofsuitabledepth.Oncompletionoftheworks,eachgratingshallbeliftedandtheframeandseatingcleaned.

509 testing and cleaning

1 DrainsrequiredinAppendix5/1tohavewatertightjointsshallbetestedasdescribedinAppendix1/5insections,eg.betweenchambers,bymeansoftheairtestdescribedinsub-Clause2ofthisClause.Ifapipelineisrejectedbecauseofafailedairtest,aspartoftherectificationwork,awatertestasdescribedinsub-Clause3ofthisClausemaybecarriedoutasanalternativeacceptabilitytest.Beforetesting,theendsofthepipelinetobetested,includingthoseofshortbranches,shallbepluggedandsealed.

2 Forthepipelineairtest,airshallbepumpedinbysuitablemeansuntilastablepressureof100mmheadofwaterisindicatedinaU-tubeconnectedtothesystem.Theairpressureshallnotfalltolessthan75mmheadofwaterduringaperiodof5minuteswithoutfurtherpumping,afteraninitialperiodtoallowstabilization.Drainswithtrapsshallbetestedto50mmheadofwaterandthepermissiblelossshallthenbenomorethan13mmheadofwaterin5minuteswithoutfurtherpumpingaftertheinitialstabilisingperiod.

3 Forthepipelinewatertest,thepipesshallbefilledwithwaterunderaheadofnotlessthan1.2mabovethe

crownofthepipeatthehighendandnotmorethan6mabovethepipeatthelowend.Steeplygradedpipelinesshallbetestedinsectionssothattheabovemaximumisnotexceeded.Thetestshallcommencenotlessthantwohoursafterfillingthetestsectionatwhichtimethelevelofwaterattheverticalfeedpipeshallbemadeuptoproducetherequired1.2mminimumtesthead.Thelossofwaterovera30minuteperiodshallbemeasuredbyaddingwateratregular10minuteintervalstorestoretheoriginalwaterlevelandrecordingtheamountssoadded.Thedrainwillhavepassedthetestifthevolumeofwateraddeddoesnotexceedonelitreperhourperlinearmetreofdrainpermetreofnominalinternaldiameter.

4 (05/01)Allpipelineslessthan350mmdiameter,excludingserviceductsshallbecheckedbydrawingthrougheachcompletedlengthofpipeasphericalmandrelofadiameter10%lessthanthenominalboreofthepipesbeingtested.

5 (11/04)DuringtheprogressoftheWorksallexistingchambers,gulliesandroddingeyesshallbekeptcleanandfreefromobstruction.OncompletionofthewholeoftheWorks,allchambers,gulliesanddrainsincludingverge/surfacewaterdrainsandfilterdrainsbutexcludingallfinandnarrowfilterdrainsshallbeflushedfromendtoendwithwaterandleftfreefromobstructions.Catchpitchambersshallbeleftcleanandfreefromsilt.

UnlessotherwiserequiredinAppendix90/1(MCHW5.9.3)allcarrier,foulandfilterdrainsbutexcludingallfinandnarrowfilterdrainsshallbesurveyedbyClosedCircuitTelevision(CCTV)inaccordancewiththerelevantrequirementsofSeries9000(MCHW5.9,Parts1to5).Furtherguidanceisprovdedinsub-ClausesNG509.4andNG509.5.

6 Thepipesandfiltermaterialoffilterdrainsshallatalltimesbeleftcleanandfreefromsiltandobstruction.

7 WheredescribedinAppendix1/5,samplesofoneormorepartlywatertightjointsforpipelinesuptoandincluding900mmdiametershallbetestedwithaheadofwaterkeptlevelwiththecrownofthepipe.Thejointwillnotbeacceptediftheflowthroughthejointinlitresperminuteexceeds20timesthesquareofthenominalinternaldiameterofthepipeinmetres.

8 PermeabilitytestsshallbeasdescribedinAppendix5/1.

9 (05/01)Serviceductsshallbecheckedbydrawingawoodenmandrel,asshownonHCDDrawingNumberI2,throughastheductsarelaidbutwhereasethastobegiventothelineofductsthewoodenmandrelshallbereplacedbyanironmandrel250mmlongbutofthesamediameterasthewoodenversion.



510 Surface Water channels and drainage channel Blocks

1 SurfacewaterchannelsanddrainagechannelblocksshallbeconstructedasdescribedinAppendix5/3.

2 SurfacewaterchannelsshallcomplywithClause1103.

3 DrainagechannelblocksshallcomplywithClause1101.

511 Land drains

1 (11/03)ExistinglanddrainswhicharepermanentlyseveredbytheWorksshallbelocatedandconnectedintoanewdrain,pipeorditchallasdescribedinAppendix5/1.ThelengthsremainingwithintheWorksshallbecleanedoutfromthenewdraintrenchfaceasnecessary.AnypipedisturbedbytheWorksshallbere-laidtoensureafreedischargeintothenewdrain.DisusedendsofinterceptedlanddrainsshallbeadequatelysealedwithST2concreteincompliancewithClause2602.

2 Whereanexistinglanddrainisexposedandseveredbytemporarytrenchexcavation,theContractorshallmarkthepositionofthedrainandrecordit.Thedrainshallbedivertedintoanexistingdrainorwatercourse.Alternatively,thenormalfunctioningofthedrainshallbecontinuedbytheconstructionofapipelineorchanneladequatelysupportedacrosstheexcavation,untilpermanentrestorationismadeontheoriginalline.

3 TheContractorshallnotifytheOverseeingOrganisationofanylanddrainwhichisblockedorisotherwisedefectivewhenthedrainisfirstexposed.

4 Severedmoledrainsshallbeledstraightintonewdrains;alternativelytheyshallwhererequiredinAppendix5/1beinterceptedbytheconstructionofalanddrain.WheretheyhavebeendisturbedmolechannelsshallbecleanedoutandfilledlocallywithTypeAfiltermaterialorasotherwisedescribedinAppendix5/1.

512 Backfilling to Pipe Bays and verges on Bridges

1 (05/04)UnlessotherwisedescribedinAppendix5/1,fillingtopipebaysandvergesonbridgesshallbewellgradedgranularmaterialnotexceeding20mmsizecontainingnotmorethan3%ofmaterialpassingthe0.063mmsieveandwithauniformitycoefficientofmorethan5.Itshallbelaidandcompactedincompliancewithsub-Clause505.6and7.Thematerial

shallmeetthesulfaterequirementdescribedinsub-Clauses503.4,503.5,505.4and505.5.

513 Permeable Backing to Earth Retaining Structures

1 UnlessotherwisedescribedinAppendix5/1,permeablebackingshallconsistofoneofthefollowingmaterialsexceptwhenthefillingadjacenttothestructureisselectedcohesivematerial(Class7A),selectedconditionedpulverised-fuelash(Class7B)orchalk:

(i) Aminimumthicknessof300mmofgranularmaterialcomplyingwiththerequirementsofClause505forTypeAorTypeCmaterialand,inaddition,satisfyingthefollowingcriteria:

Pipingratio,definedas

15percentsizeofthedrainagematerial,

85percentsizeofthebackfillmaterial

Permeabilityratio,definedas

15percentsizeofthedrainagematerial,

15percentsizeofthebackfillmaterial

wherethepercentsizeofamaterialisthesizeofparticlecorrespondingtothegivenpercentordinateoftheparticlesizedistributiongraph.

(ii) Porousno-finesconcrete,castinsitu225mmthickcomplyingwiththerequirementsofClause2603.

(iii) (05/08)PrecasthollowconcreteblockscomplyingwiththeBSEN771-3laidinstretcherbondwithdryjointsin225mmthickwallingwithholesvertical.

2 (11/03)Whenthefillingadjacenttothestructureisselectedcohesivematerial(Class7A),selectedconditionedpulverised-fuelash(Class7B)orchalk,thepermeablebackingshallbeaminimumthicknessof300mmof0/4or0/2,CPorMP,sandcomplyingwithBSEN12620unlessotherwisedescribedinAppendix5/1.

514 Fin drains

general

1 FindrainsshallcomplywiththisClauseandthespecialrequirementsdescribedinAppendix5/4.Thetermsthickness,width,heightandcoreshallhavethemeaningsindicatedonHCDDrawingNumberF18unlessotherwisedescribedinAppendix5/4.


<5

>5


Thetermfindrainshallmeanaplanargeocompositestructuredesignedtoperformthesamefunctionasanarrowfilterdrain.2 Wherefindrainsaredesignedforlateralentryofwaterfromonesideonlytherequirementsforflowratesinsub-Clauses4and5ofthisClauseshallapplytothefaceorplanedesignedtoadmitortransmitwater.3 Thematerialsofwhichthedrainismadeshallbetreatedsothattheyareprotectedfromthedeleteriouseffectsofshorttermexposuretoultravioletlight,andshallberesistanttodegradationbyacids,alkalis,commonchemicals,bacteria,fungiandmouldsoccurringinsoilsandhighwayconstructionmaterials.AfterexposuretoultravioletlighttheOverseeingOrganisationmayrequireevidencethatthematerialsstillcomplywiththerequirementsofthisClause.Thedrainshallbeprotectedfromdamageandultravioletlightandbelabelledtoidentifythegradeandmanufacturerorsupplier.Wherenecessary,thesideintendedforentryofwaterandthedirectionofin-planeflowshallbeidentified.

geotextile

4 Thegeotextileshall:

(i) (11/03)inbothmachineandcross-machinedirections,sustainatensileloadofnotlessthan5.0kN/matbreakandhaveaminimumfailurestrainof10%whendeterminedinaccordancewithBSENISO10319;

(ii) (11/03)haveaminimumpunctureresistanceof1200NwhendeterminedinaccordancewithBSENISO12236;

(iii) (11/03)haveaminimumtearresistanceof200NwhendeterminedinaccordancewithASTMStandardD4533-91(1996);

(iv) haveasizedistributionofporeopeningssuchthattheapparentopeningsizeO90whendeterminedinaccordancewithBS6906:Part2,orotherappropriatetest,isasstatedinAppendix5/4;

(v) allowwatertoflowthroughit,ineitherdirection,normaltoitsprincipalplaneatarateofnotlessthanthatstatedinAppendix5/4underaconstantheadofwaterof100mmandamaximumbreakthroughheadof50mmwhendeterminedinaccordancewithBS6906:Part3.

composite drain

5 (05/01)Thecompositedrainshall:

(i) haveaflowratethrougheachfaceofthedrainofmorethan75%ofthevalue

specifiedinsub-Clause4(v)ofthisClauseonthesideorsideswhereinflowoccurs.Thisvaluemaybefoundbyeither:

(a) directmeasurementofthecompositedrainusingamodifiedversionofBS6906:Part3;or

(b) calculationbasedontheflowrateobtainedbythestandardtestinBS6906:Part3andthepercentagecontactareaofthedrainagecoreobtainedfromsub-Clause13ofthisClauseorotherappropriatemethod;

(ii) havevaluesoflongtermin-planeflowratesasstatedinAppendix5/4whendeterminedinaccordancewithsub-Clauses14and15ofthisClause.ThevaluesofhydraulicgradientandminimumappliedstressesshallbeasgiveninTable5/7.

taBLE 5/7: (05/01) applied Stresses (kn/m²) and Hydraulic gradient

Hcd drain type 5 6 7 10Sub-Clause14:NormalStressShearStress

5010

5010

5010

10010

Sub-Clause15:NormalStress

100

100

100

100

Sub-Clause15:HydraulicGradient

0.11.0

1.0

1.0

0.11.0

Joints6 Findrainsshallbecapableofbeingjointedlongitudinallyorlaterallyintopipesystemsorchambersforinflowandoutflowpurposesandbeselfjointingeitherdirectlyorthroughpurposemadeattachmentpiecesforformingcontinuousdrainlengths.Allsuchjointsshallbeformedsoastopreventtheingressofsoilparticlesorotherextraneousmaterialintothedrain.

Findrainjointstransversetothedirectionofflowshallhavevaluesofin-planeflowratesnotlessthanthatrequiredbysub-Clause5(ii)ofthisClause.

Findrainjointsparalleltothedirectionofflowandanyexposededgesshallbeprotectedfromtheingressofsoilbyageotextilewrappingwithaminimumoverlapof150mm.

Pipes

7 (11/06)FordrainType6pipesshallbeperforatedorporousandcomplywithsub-Clause501.3.Pipes



complyingwithBS4962:1989shallhaveaminimumUltimatePipeStiffness(STES)valueof1400N/m2.

FordrainType7pipesshallbeunperforatedthermoplasticspipecomplyingwithBS4660,BS5481,BSEN1401,BSEN1852-1orBSEN12666-1slottedlongitudinallyalongthetopsurfaceandstressrelieftreated(ifrequired)inaccordancewiththesystemmanufacturer’spublishedspecification.

8 (05/01)PipejointsshallcomplywiththerequirementsoftherelevantBritishStandardforthepipeusedorClause518.

Backfill and Surround Material

9 PipesurroundmaterialfordrainTypes6and7shallcomplywithsub-Clause503.3(i)or503.3(ii)orTypeAorCmaterialcomplyingwithsub-Clause505.3.

Wherefindrainsareinstalledinatrenchbackfillmaterialshallbetheoriginalas-dugmaterialfromthetrenchunlessotherwisespecifiedinAppendix5/4.

dimensions

10 (11/03)UnlessotherwisedescribedinAppendix5/4thedimensionsofthefindrainshallbeasshownonHCDDrawingsF18andF21.ThepipediametershallbeasstatedinAppendix5/4.Thedrainslopeangle(x),asshownonDrawingF19,shallbenotgreaterthan15%fromtheverticalunlessotherwisestatedinAppendix5/4.

Installation and Handling

11 InstallationoffindrainsshallbeasshownonHCDDrawingNumbersF19toF21.Wherefindrainsareassembledonsitetheassemblyareashallbecleananddryandfreeofwind-bornepollutants.Anymaterialwhichbecomescontaminatedmustbereplaced.Nogeotextileorcorematerialshallbeexposedtodaylight(oranysourceofultravioletradiation)foraperiodexceedingacumulativetotalof50hours.Anygeotextileorcorematerialexposedtodaylight(oranysourceofultravioletlight)foraperiodexceedingacumulativetotalof50hoursshallbereplacedunlessitcanbedemonstratedthatthematerialsofthedrainstillcomplywiththerequirementsofthisClause.

Wherefindrainsarelaidintrench,thetrenchbottomshallbefreeofirregularitiesandtotherequiredlevelsgiveninAppendix5/4.Rockandotherhardprotuberancesshallberemovedandanyexcesscutinthetrenchbottomfilledandcompactedbacktotherequiredgradewithsuitableexcavatedorimportedmaterial.

Thedrainshallbelaidwiththeappropriatefaceagainstthesideofthetrenchadjacenttothecarriagewayandin

theappropriatedirection.Thissideofthetrenchshallhavewallssufficientlycleantoenablethefindraintocomeintoclosecontactwiththewallwhenthetrenchisbackfilledandcompacted.CompactionshallbeinaccordancewithClause612.FindrainsinstalledaspartofthePermanentWorksshallbeprotectedfromsurfacewater,contamination,andaccidentaldamageduringconstruction.

Thefindrain,pipesurroundandbackfillshallbeinstalledsoastocausenodamagetothefindrain.Whereanydamagedoesoccur,thedamagedmaterialsshallbereplacedbynewmaterial.

Aftertheinstallationofthefindrainhasbeencompletedamarkertapeshallbelaidapproximately75mmabovethefindraininthepositionshownonHCDDrawingNumbersF19andF20.Thetapesshallbegreenself-colouredPVCorpolytheneplasticnotlessthan0.1mmthickand150mmwide.

Identification

12 TheContractorshallobtainandmakeavailablethefollowinginformationforeachseparateconsignmentoffindraindeliveredtoSite:

(i) geotextileandcorename,grade/numberandmassperunitarea;

(ii) namesandaddressesofsystemproducer,andgeotextile,coreandpipemanufacturers;

(iii) manufacturingcharacteristicsandconstituentsofgeotextileandcore.Thisshallincludecompositionandtypeofconstituentfilaments,threads,fibres,films,tapesandothercomponents;

(iv) consignmentnumberanddeliverydate;

(v) acopyofthesitedeliverynote.

test Method for the Percentage contact area of drainage core

13 (i) Thetestdeterminestheareaofonefaceofadrainagecorewhichwillbeincontactwithageotextilefilterasapercentage.

(ii) Theapparatusrequiredisasfollows:

(a) loadingdeviceabletoapplyacompressiveloadofatleast2kNandhavingaflatsteelbase;

(b) flatsteelloadingplate200mmx200mm;

(c) printersinkandroller(orpad);

(d) sheetofthincompressiblerubber;

(e) planimeter.



(iii) Thetestprocedureshallbeasfollows.Cutthreerepresentativetestspecimens200mmx200mm(±2mm).Applyinktoone200mmx200mmfaceofaspecimenandcoverwithasheetofplainpaperandathincompressiblerubbersheet.Placethepreparedspecimenintotheloadingdeviceandgraduallyapplytheloadof2kNandmaintainfor5minutes.Releasetheloadandremovethespecimenandseparateitfromthepaper.Usingtheplanimeterfindthetotalareaofthepaperwhichhasreceivedanimprint.Repeatforallspecimens.

(iv) Thepercentagecontactarea=

totalareaofimprint

areaoftestspecimen

(v) Thereportshallinclude:

(a) areferencetothismethod;

(b) sampleidentificationdetails;

(c) individualandmeanpercentagecontactareas;

(d) detailsofanydeviationfromthespecifiedtestprocedure.

(vi) AlternativemethodsofdeterminingthepercentagecontactareamaybeemployedwiththepriorapprovaloftheOverseeingOrganisation.

test Method for determining the thickness of Fin drains under Specified normal and Shear Stresses

14 (i) (05/01)Thetestdeterminesthethicknessofthefindrainundersustainednormalandshearstresses.Alongtermthickness(at100,000hours)iscalculatedbyextrapolationandashorttermequivalentnormalloadwhichproducesthelongtermthicknessisdetermined.

(ii) Theapparatusrequiredisasfollows:

(a) asuitablecompressiontestingmachine,whichshallhaveaverticaltravelatleastthenominalthicknessofthespecimen.Itshallbecapableofsustainingthenecessaryloadstowithin1%accuracyforthedurationofthetest;

(b) thecompressiontestingapparatus,whichshallincludeafixedbaseplateandparallelmoveabletopplatewithflatsteelsurfacewithsufficientfrictiontopermitthedevelopmentoftherequiredshearforces;

(c) ameansofmeasuringthemeanthicknessofthespecimentoanaccuracyof0.01mm.

Asanalternativeto(a)and(b),anappropriateinclinedplaneandkentledgesystemmaybeemployedtoproducethenormalandshearloads.

Thetestprocedureshallbeasfollows:

(iii) Cutsixrepresentativespecimensofminimumsize100mmx100mmsymmetricallyaboutthecoredesign.Threespecimensshallbetestedinaccordancewith(v)belowandthreeinaccordancewith(vi)below.

(iv) Thetestspecimenshallbeplacedsymmetricallyonthebaseplateandcoveredbythetopplate.Themeansofmeasuringthicknessshallbeattachedandtheinitialthicknessmeasured.

(v) (11/03)Applytheloadsmoothlyandasquicklyaspossibletothetopplate.Thefullload(normalandshear)shallbeappliedinlessthan20secondsandsustainedforatleast1000hours.TheappliedstressesshallbethosegiveninTable5/7.Atleastfourmeasurementsofthicknessshallbemadeduringeachunitoflogarithmictimeafterthefirstminute.Determinethelongtermthicknessofthespecimenasthethicknessofthespecimenat1000hoursreducedby2TwhereTisthedifferenceinthicknessesofthespecimenthicknessrecordedat100hoursand1000hours.Repeatthetestonthetwootherspecimens.Thetestspecimensshallbemaintainedataconstanttemperatureof20°C±2°Cthroughoutthetestperiod.

(vi) Applyincreasingincrementsofnormalloadtothespecimen.Determinetheshorttermequivalentloadwhichshallbetheloadwhichwhenappliedforaperiodof20±5minutesproducesaspecimenthicknessequal(withinanaccuracyof±0.05mm)tothelongtermthicknessofthespecimenobtainedat(v)above.Repeatthetestontheothertwospecimens.

(vii) Thereportshallinclude:

(a) areferencetothismethod;

(b) sampleidentificationdetails;

(c) theinitialthicknessofthesample;

(d) theappliedload;


x100


(e) thethicknessofeachsampleat100and1000hoursandthemeanofthethreeresults;

(f) aplotofpercentagereductioninthicknessagainstlogarithmictime;

(g) themeanlongtermthickness;

(h) themeanshorttermequivalentload;

(i) anydeviationsfromthespecifiedtestprocedure.

determining In-plane Flow under compressive Loading

15 (05/01)In-planeflowshallbedeterminedinaccordancewithBS6906:Part7exceptthatthefollowingconditionsshallapply:

(a) theappliednormalstressshallbethegreaterofthevaluegiveninTable5/7(forsub-Clause15)orthemeanshorttermequivalentstressasdeterminedinsub-Clause14(vi)ofthisClause;

(b) thesampleshallbetestedsuchthatthemeasuredflow(orflows)isinthesamedirectionastheprincipalflow(orflows)whenthefindrainisinservice;

(c) thefoamrubberoptionofthetestprocedureshallbeused(detailsofthefoamrubbertobeusedmaybeobtainedfromtheOverseeingOrganisation);

(d) thehydraulictransmissivityshallbereportedforeachofthehydraulicgradientsemployed.

test Methods

16 Notwithstandingtherequirementsofsub-Clauses13,14and15ofthisClause,variationsinthetestmethodsspecifiedthereinshallbemadewheredeemednecessarybytheBritishBoardofAgrémentfollowingconsultationwiththemanufacturer.Allsuchvariationsshallberecordedinthereport.

certification

17 FindrainsandconstituentmaterialsshallhaveacurrentBritishBoardofAgrémentRoadsandBridgesCertificatecertifyingtheappropriatephysicalpropertieswhentestedinaccordancewiththisClause.

515 narrow Filter drains

general

1 NarrowfilterdrainsshallcomplywiththisClauseandthespecialrequirementsdescribedinAppendix5/4.

ThetermnarrowfilterdrainreferstodrainTypes8or9indicatedintheHCDDrawingNumberF18.Theyconsistofaporousorperforatedpipelaidinanarrowtrenchsurroundedbygranularmaterialwherethegranularmaterialand/orthepipeisenclosedbyalayerofgeotextilefilter.Narrowfilterdrainsandfindrainsperformthesamefunction.

Materials

2 Thegeotextilematerialsusedinthedrainshallbestoredsothattheyareprotectedfromthedeleteriouseffectsofshorttermexposuretoultravioletlight,andshallberesistanttodegradationbyacids,alkalis,commonchemicals,bacteria,fungiandmouldsoccurringinsoilsandhighwayconstructionmaterials.AfterexposuretoultravioletlighttheOverseeingOrganisationmayrequireevidencethatthematerialsstillcomplywiththerequirementsofthisClause.Theyshallbeprotectedfromdamageandultravioletlightandbelabelledtoidentifythegradeandmanufacturerorsupplier.

3 Thegeotextileusedinnarrowfilterdrainsshallcomplywithallrequirementsofsub-Clause514.4forgeotextilesusedinfindrains.

FordrainType8thegeotextilesurroundtothepipeshallconsistofaprefabricatedcontinuousclosefittingsock.Alternativelythepipeshallbefirmlywrappedinasinglelayerofgeotextilewithanoverlapofbetween50and75mmandsecuredaroundthepipeinamannersoastopreventtheingressofsoilparticlesorotherextraneousmaterialandwithoutaffectingthepermeabilityofthewrappedmaterial.Splicesbetweenlengthsofsockorlayershallhaveoverlapswithinthesedimensionsandbesecurelytied.

FordrainType9thegeotextilesurroundtothegranularmaterialshallhaveaminimumoverlapof250mmincluding100mmdown-tuck.Splicingoflengthsofgeotextileshallconsistofminimum600mmoverlapsecuredwithpinsormechanicalties.Whereanoutletpipepassesthroughthegeotextileaseparatepieceofgeotextileshallbewrappedroundtheoutletpipe,flaredagainstthegeotextileinthefilterdrainandsecured.Wheredrainlengthsareterminatedatchambers,thegeotextileshallbesecuredagainstthechamberwallsbysuitablemeanssoastopreventtheingressofsoilparticlesorotherextraneousmaterialintothedrain.

4 (05/01)Pipesandfittingsshallcomplywithsub-Clauses514.7and514.8.WherecoilablepipestoBS4962:1989areusedtheyshallbecapableofbeingstraightenedsoastolieflatwithoutrestraintinthetrenchbottombeforebackfilling.

5 (11/03)Thegranularmaterialusedfortrenchinfillshallcomplywiththerequirementsfornon-plasticity,



LAcategoryandsulfatecontentofsub-Clause505.3andhaveagradingwithinthelimitsofTable5/8.Thematerialwhentestedinaccordancewithsub-Clause509.8shallmeetthepermeabilityrequirementsdescribedinAppendix5/4.

taBLE 5/8:(11/03)narrow Filter drain: trench Infill grading Requirements

HCDDrainType 8 9MaximumParticleSizemm

40 40

D5Sizemm >0.125 >0.125D15Sizemm Asstatedin

Appendix5/4-

D85Sizemm - >HoleDiameteror1.2TimesWidthofSlotinPipe

UniformityCoefficient 5to12 5to12orifCu<5(Cu)D60/D10 D5>1mm

Dn=Sievesizepassingn%byweightofmaterial

dimensions

6 UnlessotherwisedescribedinAppendix5/4thedimensionsofthenarrowfilterdrainshallbeasshownonHCDDrawingNo.F18.ThepipediametershallbeasstatedinAppendix5/4.Thedrainslopeangle(x),asshownonDrawingF20,shallbenotgreaterthan15%fromtheverticalunlessotherwisestatedinAppendix5/4.


7 NarrowfilterdrainsshallbeinstalledasshownonHCDDrawingNumberF20.Beforeduringandafterinstallationthegeotextileshallbeprotectedfromcontamination,damageandexposuretoultravioletradiationinaccordancewithsub-Clause514.11.

TheexcavatedtrenchbottomshallbefreeofirregularitiesandtotherequiredlevelsgiveninAppendix5/4.Rockandotherhardprotuberancesshallberemovedandanyexcesscutinthetrenchbottomfilledandcompactedbacktotherequiredgradewithsuitableexcavatedorimportedmaterial.DrainType9shallhavetrenchwallssufficientlycleantoenablethegeotextiletocomeintoclosecontactwiththewallwhenthegranularmaterialisplacedinsideit.Thedepositionandcompactionofinfillshallbeinaccordancewithsub-Clause505.4forfilterdrains.

NarrowfilterdrainsinstalledaspartofthePermanentWorksshallnotbeusedforthedisposalofsurfacewaterrun-offduringconstruction.Narrowfilterdrains

exposedtosurfacewateringressshallbetemporarilyprotected.

Markertapesshallconformandbeinstalledinaccordancewithsub-Clause514.11.

8 TheContractorshallobtainandmakeavailabletheinformationrequiredinsub-Clause514.12inrespectofthegeotextileandpipe.

certification

9 ThegeotextileshallhaveacurrentBritishBoardofAgrémentRoadsandBridgesCertificatecertifyingtheappropriatephysicalpropertieswhentestedinaccordancewiththisClause.

516 combined drainage and Kerb Systems

(11/04) general

1 (11/04)CombineddrainageandkerbsystemslistedinAppendix1/11shallbetreatedasotherfeaturestobedesignedbytheContractor.CombineddrainageandkerbsystemsshallconformtoBSEN1433andtothespecialrequirementsinAppendix5/5.

2 (11/04)CombineddrainageandkerbsystemsshallbesuitablefortheirintendeduseandplaceofinstallationintheWorksandasstatedinAppendix5/1.TheContractorshallprovideevidenceofsuchsuitabilityforthepurposetotheOverseeingOrganisationinaccordancewithAppendix1/5.

3 (11/04)DesignflowsgiveninAppendix5/5shallbeaccommodatedwithoutsurchargewithinthemaincombineddrainageandkerbsectionandbeneaththeundersideofanyinletslotsections.

4 (11/04)Whereapplicable,thewidthanddepthofcombineddrainageandkerbsystemunitsshallnotexceedthedimensionsgiveninAppendix5/5.

5 (11/04)Whenusedadjacenttoporousasphaltsurfacingmaterials,unitsshallincorporatesideentryinletstopermitdrainageofwaterheldwithintheproousasphalt.InletsshallcomplywiththerequirementsofAppendix5/5andshallhavethecapacitytodrainporousasphalt.

(11/04) classification

6 (11/04)Combineddrainageandkerbsystems,excludingin-situsystem,shallbeclassifiedasfollowsaccordingtotheirintendeduseandshallbeasstatedinAppendix5/5:

(i) C250:

(ii) D400;and



(iii) where,exceptionally,combinedkerbanddrainageunitshavetobelocatedinareassubjectedtolargenumbersofhighspeedheavygoodsvehicles,ClassE600combinedkerbanddrainageunitsshallbeconsidered.

(11/04) Water tightness

7 (11/04)Jointsbetweenunitscomprisingthesystemandbetweenthechannelandunits,shallbedesignedtoavoidleakageofsurfacewater.Jointsbetweenbridgedeckwaterproofingandcomponentpartspassingthroughthewaterproofingshallbewatertight.Sealantsshallbecompatiblewiththewaterproofingsystem.

(11/04) Installation and Handling

8 (11/04)Combineddrainageandkerbsystemsshallbelaidandjointedinaccordancewiththemanufacturer’swritteninstructions.

9 (11/04)Adjacentcarriageway,footway,vergeorcentralreservetobedding,backing,surroundingorjointingofcombineddrainageandkerbunitsshallbeinaccordancewiththemanufacturer’swritteninstructions.

10 (11/04)Junctions,connectingpipesandotherfittingscomprisingthecombineddrainageandkerbsystemshallcomplywithsub-Clause501.3andshallbeasdescribedinAppendix5/5.Thecombineddrainageandkerbsystemshallincorporatemeasurestoenableroddingoftheoutfallpipeworkandadequateaccessforjettingbywaterjettingequipmentintothesystem.

(11/04) cleaning

11 (11/04)Combineddrainageandkerbsystemsshallbecleanedoutbyappropriatemeansandshallbeleftcleanandfreefromallobstruction.ThecompletedcombineddrainageandkerbsystemsshallbesurveyedbyClosedCircuitTelevision(CCTV)inaccordancewiththerelevantrequirementsofSeries9000(MCHW5.9,Parts1to5).

517 Linear drainage channel Systems

general

1 (11/04)ThelineardrainagechannelsystemslistedinAppendix1/11shallbetreatedasotherfeaturestobedesignedbytheContractor.Thein-situlineardrainagechannelsystemsshallconform,whereapplicable,tosub-Clauses517.2to517.17andtherequirementsinAppendix5/6andAppendix1/11asappropriate.Theprefabricatedlineardrainagechannelsystems,whereapplicable,shallconformtoBSEN1433andwiththeotherrequirementsinAppendix1/5.

2 (11/04)LineardrainagechannelsystemsshallbesuitablefortheirintendeduseandplaceofinstallationintheWorks.TheContractorshallprovideevidenceofsuchsuitabilityforthepurposetotheOverseeingOrganisationinaccordancewithAppendix1/5.

3 DesignflowsgiveninAppendix5/6shallbeaccommodatedwithoutsurchargewithinthemainchannelsectionandbeneaththeundersideofanyinletslotsections.

4 (11/04)Whereapplicable,thewidthanddepthoflineardrainagechannelsystemunitsshallnotexceedthedimensionsgiveninAppendix5/6.

5 (11/04)Dimensionsofinletslotsshallcomplywiththefollowingcriteria:

(i) forprefabricatedlineardrainagechannelsystemstheyshallconformtoBSEN1433;

(ii) forin-situlineardrainagechannelsystemstheyshallconformtoBSEN1433.

6 (11/04)Whenusedadjacenttoporousasphaltsurfacingmaterials,unitsshallalsoincorporatesideentryinletstopermitdrainageofwaterheldwithintheporousasphalt.InletsshallcomplywiththerequirementsofAppendix5/6andshallhavethecapacitytodrainporousasphalt.

(11/04) Weathering Resistance

7 (11/04)MarkingrelatingtothegradeofweatheringresistancefordrainagechannelsmadeofconcreteshallbeasstatedinAppendix5/6.

(11/04) classification

8 (11/04)lineardrainagechannelsystemsshallbeclassifiedasfollowsaccordingtotheirintendeduseandshallbeasstatedinAppendix5/6:

(i) C250;

(ii) D400;and

(iii) where,exceptionally,lineardrainagechannelsystemshavetobelocatedinareassubjectedtolargenumbersofhighspeedheavygoodsvehicles,ClassE600combinedkerbanddrainageunitsshallbeconsidered.

(11/04) Water tightness

9 (11/04)Jointsbetweenunitscomprisingthesystemandbetweenadjacentconstructionandthesystemshallbedesignedtoavoidleakageofsurfacewater.Whereapplicable,jointsbetweenbridgedeckwaterproofingandcomponentpartspassingthroughthewaterproofingshallbewatertight.Sealantsshallalsobecompatiblewiththewaterproofingsystem.



10 (11/04)Junctions,connectingpipesandotherfittingscomprisingthelineardrainagechannelsystemshallcomplywithsub-Clause501.3andshallbeasdescribedinAppendix5/6.Thelineardrainagechannelsystemshallincorporatemeasurestoenableroddingoftheoutfallpipeworkandadequateaccessforjettingbywaterjettingequipmentintothesystem.

(11/04) cleaning

11 (11/04)ThelineardrainagechannelsystemsshallbecleanedoutbyappropriatemeansandshallbeleftcleanandfreefromallobstructiononcompletionoftheWorks.ThecompletedlineardrainagechannelsystemsshallbesurveyedbyClosedCircuitTelevision(CCTV)inaccordancewiththerelevantrequirementsofSeries9000(MCHW5.9,Parts1to5).Furtherguidanceisprovidedinsub-ClausesNG509.4andNG509.5.

Manufactured Systems

12 (11/04)ManufacturedsystemsshallconformtoBSEN1433.

In Situ Systems

13 (11/04)In-situsystemsshallcomplywiththerequirementsofsub-Clauses1103.1,1103.3and1103.4.Theyshallalsocomplywiththerequirementsofsub-Clause1103.2exceptthattheconcreteshallbeconsideredasplainconcretewithinthetermsofthissub-Clause,irrespectiveoftheinclusionofreinforcement.

14 (11/04)In-situsystemsshallbeslipformedexceptforsectionsatgullieswhichshallbehandformed.Fulldepthjointsshallbeconstructedattheinterfaceateachsideofgullieswitha25mmthickfillerboardcomplyingwithClause1015andsealedinaccordancewithClauses1016and1017.

15 (11/04)Thecentralvoidmaybeformedbyaninflatedtubewhichisthenremoved,orbyaninsitusuitablepipeorsimilarformerfitforthepurpose.Atgullypositionstheinnerformershallbepre-sleevedwithasuitablepipeorsimilarformerfitforthepurposewhichshallbeofsufficientlengthtooverlapthetwojointsoneithersideofthegully.

16 (11/04)Thecentralvoidshallbecheckedinaccordancewithsub-Clause509.4.Verificationofslotwidthsshallbedeterminedbysuitabletemplates.

17 (11/04)ReinforcementshallcomplywithSeries1700.Covertoreinforcementshallbenotlessthan75mm.

18 (11/04)Triallengthsandtestingofin-situchannelsshallbeundertakeninaccordancewithclauses6and8.6ofBS5931andtherelevantparagraphsofclause9ofBSEN1433respectively.

518 (05/01) thermoplastics Structured Wall Pipes and Fittings

general

1 ThermoplasticsstructuredwallpipeshallcomplywiththisClauseandthespecialrequirementsdescribedinAppendix5/1.

Thetermstructuredwallpipeshallmeanalltypesofsmoothborepipeexceptsolidwallhomogeneouspipe.Typicalformsofconstructionclassifiedasstructuredwallpipesinclude:singlewallexternallystructuredsmoothbore,twinwall,foamedcoreandspirallywound.

Thetermfittingshallmeanaproductusedinconjunctionwiththepipetoformthesystembutexcludinggulliesmanholechambers,inspectionchambersandaccesschambers.

Materials

2 Thematerialsfromwhichthepipeandfittingsaremade,shallbetreatedsothattheyareprotectedfromthedeleteriouseffectsofshorttermexposuretoultravioletlight,andshallberesistanttodegradationbyacids,alkalis,commonchemicals,bacteria,fungiandmouldsoccurringinsoil,highwayconstructionmaterialsandhighwaydrainagesystems.Inaddition,thematerialsfromwhichthepipeandfittingsaremade,shallnotincorporateanyadditivesinquantitiessufficienttocausemicrobiologicaldegradationortoimpairtheconformitytothechemical,physicalandmechanicalpropertiesorimpactresistancerequirementsgiveninsub-Clause5ofthisClause.Thespecificationoftherawmaterialshallbeagreedbetweenthecertificationbody,asdefinedinsub-Clause15ofthisClause,andthemanufacturerandmayincorporatere-processableand/orrecyclablematerial.TheagreedspecificationshallincorporatetolerancesforeachoftherelevantcharacteristicsdefinedintheappropriateclauseofprEN13476.TheContractorshallsubmittotheOverseeingOrganisation,priortocommencementoftheWorks,completedinformationsheetsinaccordancewithAppendix5/7.

dimensions

3 Systemsforcarrierdrainageshallbebetween150mmand900mmnominalinternaldiameter.Pipesfornarrowfilterdrainsshallbe110mmor150mmnominalinternaldiameter.Pipesforserviceductsshallhavenominalinternaldiametersofbetween50mmand150mm.Pipesforsub-soildrainageshallincorporateslotsorholeswithaminimumcrosssectionalareaof1000mm2permetrerunofpipe.



TheboreofthepipeandfittingsshallbeinaccordancewiththestandardtolerancesfornominalboresgiveninBSEN476.

appearance

4 (05/06)Thesystemshallhaveasmoothboreandbefreefromanyburs,flashorotherinconsistenciesthatcouldhaveadetrimentaleffectontheperformanceofthesystem.Pipesandfittingsfordrainageshallbe

externallycolouredeitherterracottaorblack.ThecolourofductingpipesshallbeinaccordancewithNationalJointUtilitiesGrouppublication“GuidelinesonthePositioningandColourCodingofUtilities’Apparatus”.AnyvariationinthecolourshallbedescribedinAppendix5/2.

Structured Wall Pipe

5 ThestructuredwallpipeshallhavethepropertiesdefinedinTable5/9.

Amendment-May2006 22

taBLE 5/9:(11/03)Requirements for Structured Wall Pipe

Property Relevant Standard RequirementGeneral BSENISO2897-1,

BSENISO2897-2andBSISO11922-1

Dimensionstobespecified

Ringstiffness BSENISO9969 6kN/m2minimum.LowerstiffnessvaluesarepermittedifdesigncalculationstoBSEN1295-1(UKnationalannex),basedonsitespecificinstallationconditions,indicatesatisfactoryperformance.)

CreepRatio BSENISO9967 PVC-U -maximum2.5PPandPE -maximum4.0

Highvolumelowpressurejetting WRcJettingTestMethod Minimumacceptablefailurepressure137bar.Longitudinalbending sub-Clause518.11 Pipeswithnominaldiameters≤350mmtohaveadifferencein

dimensionswhenmeasuredintheverticalaxisoflessthan5%ofthepipelengthandnolocalpermanentdeformationoccursduringthetest.

Impactresistanceat0ºC BSEN1411withd25strikerof1kg

Preliminarytest–test10piecesasdescribedinBSEN1411,droppingthestrikerfromaheightof1m.Ifanytestpiecesfail,subjectthepipetothefulltestgiveninclause7.3ofBSEN1411startingthestrikerfromadropheightof400mm.Themeanminus1.64timesthestandarddeviationmustexceed1m.

Impactresistanceat23ºC BSEN1411withstrikerasabove

Valuetobederivedfromthesamebatchofpipeasusedintheimpactresistancetestat0ºC.TheH50(mean)value-10%tobeusedastheminimumvalueforqualitycontroltesting.Alternativelythe0°CtestcanbeusedasaQCtestifthemanufacturerchooses.

Roddingresistance sub-Clause518.12 Pipeswithnominaldiameters≤350mmtohaveanaveragefailureenergy>3joules

Staticfrictioncoefficient(ducts) TS12-24 PassCreepatelevatedtemperature(ducts)

BSENISO9967 Testtobecarriedoutat45ºC,creepratiotobelessthan2timesthevaluestoBSENISO9967.

Resistancetopointloads(ducts) sub-Clause518.13 Noperforationat10%rodtravelTensilestrengthofaseam BSEN1979 prEN13476

Fittings

6 ThefittingsforusewithstructuredwallpipeshallhavethepropertiesdefinedinTable5/10.



TABLE 5/10: (11/03) Requirements for Fittings

Property Relevant Standard Requirement

General BS EN ISO 2897-1, Dimensions to be specifiedBS EN ISO 2897-2 andBS EN ISO 11922-1

Ring stiffness (excluding ISO 13967 6 kN/m2 minimumcouplers)

Rodding resistance sub-Clause 518.12 Fittings with nominal diameters ≤ 350 mm to have an average failureenergy >3 joules

Strength and flexibility of BS EN 12256 BS EN 12256fabricated fittings

Impact resistance (drop test) Drop Test to BS EN Fall height 1000 mm at a temperature of 0ºC. Product less than ND12061: 1999 300 shall show ‘no damage’. Others may fail but must be identified

as ‘handle with care’

Watertightness of fabricated BS EN 1053 0.5 bar for 1 minutefittings

Pipe and Fittings

7 The pipe and fittings shall have the propertiesdefined in Table 5/11.

TABLE 5/11 (11/03) Requirements of the Systems

Property Relevant Standard Requirement

Leaktightness of joints - diameter BS EN 1277 Method 4 Use default values from BS EN 1277distortion (watertight joints) Condition B Temperature

(23 ± 2)°C

Leaktightness of joints - angular BS EN 1277 Method 4 Use default values from BS EN 1277deflection (watertight joints) Condition C Temperature

(23 ± 2)°C

Leakage rate from partially- sub-Clause 509.7 Less than 20 times the square of the ID of the pipe in metres shallwatertight joints flow through the joint in litres per minute

Resistance to wheel loads BS EN 1437 adapted to Less than 5% deformation when loaded to 100 kN (for unequalsuit HA loading conditions branches only)

23Amendment - November 2004

Bedding, Backfill and Surround Material

8 (11/03) All systems shall be installed in accordancewith the pipe and bedding combinations given inAdvice Note HA 40 (DMRB 4.2.5). Other combinationsshall be supported by calculations in accordance withBS EN 1295-1 UK National Annex. Bedding, backfilland surround materials are classified in Clause 503 andClause 505.


9 The bedding, surround and backfill shall beinstalled so as to cause no damage to the pipes andfittings. Installation of the pipe and fittings, particularly,procedures for preparation and execution of jointingoperations, shall be in accordance with themanufacturer’s instructions.



Identification

10 The Contractor shall maintain records with thefollowing information for each separate consignment ofstructured wall pipe or fittings delivered to Site:

(i) system name, ring stiffness grade/numberand size;

(ii) name and address of the systemmanufacturer;

(iii) consignment number and delivery date; and

(iv) a copy of the site delivery note.

Test Method for Longitudinal Bending

11 (i) The test specimen shall be a six metre lengthof pipe or the maximum length availablefrom the manufacturer (if less than sixmetres).

(ii) The apparatus shall include:

(a) two level support blocks at least250 mm wide and of sufficient height toallow the pipe to sag over its lengthwithout touching the ground;

(b) a means of measuring the verticaldistance between the pipe at the centreof the span and a fixed point ofreference to an accuracy of ±0.5 mm.

(iii) The test procedure shall be as follows:

(a) condition the specimen for at least1 hour at 23°C ± 2°C;

(b) set the supports at a distance apart equalto the length of pipe minus 500 mm;

(c) place the pipe symmetrically on thesupports;

(d) measure the distance between the top ofthe supports and the fixed point ofreference, in the vertical axis throughthe centre line of the pipe;

(e) after a period of two minutes measurethe distance between the underside ofthe pipe at mid span and the fixed pointof reference;

(f) record the difference in readings as apercentage of pipe length.


Test Method for Rodding Resistance (InternalPuncture)

12 (i) The test specimens shall be:

(a) twenty specimens cut from thestructured wall pipe, each specimen tobe 242 mm to 246 mm in length and aquarter section of the circumference or;

(b) twenty specimens cut from a number ofidentical fittings.


(a) a standard drop weight pipe testingapparatus capable of dropping a tupfrom a height of 1 m;

(b) a 300g tup which can be varied in 30gmultiples with a striker consisting asteel rod 18 mm in diameter with a9 mm hemispherical end;

(c) a 250 mm x 250 mm box containing dryLeighton Buzzard sand (Garside quarry)such that there is at least 100 mm ofsand beneath the test specimen whenbedded down.

(iii) Procedure shall be as follows:

(a) mark the intended point on the inside ofthe pipe on the intersection of the centrelines. With profiled pipes the point ofimpact shall be at the point nearest theintersection that mid way between theribs or in the middle of a hollowcorrugation;

(b) alternatively mark the intended point ofimpact on the section of fitting;

(c) condition the test specimens in air at atemperature of 4°C ± 2°C for a period ofat least one hour before the test;

(d) locate the box under the drop tube of theimpact apparatus;

(e) embed the specimen into the sand usinga vibrator with the inner surfaceexposed and facing upwards;

(f) locate the specimen such that themarked point of impact is under thecentre line of the tup;

(g) drop the tup from a height of 1 m on tothe inner surface of the specimen within10 seconds of removing the specimenfrom the conditioning environment;



(h) examine the specimen for damage.Damage is defined as a puncture orcrack of the inner layer. Ductile bendingor “whitening” is not considered to bedamage;

(i) (11/03) if the specimen exhibits nodamage the next test shall be conductedwith a tup of 30 g greater mass. If thespecimen does exhibit damage the nexttest shall be conducted using a tup of30 g smaller mass;

(j) after having completed the 20 strikescalculate the average of the energieswhere a pass (no damage) was recordedand the average of the energies where afailure (damage) was recorded, thencalculate the average of the twoaverages.

(iv) The test report shall include:

(a) identification of the samples;

(b) the overall average;

(c) whether or not the specimens weredamaged.

Test Method for Resistance to Sharp Objects

13 (i) Test specimens shall be three samples ofduct each 300 mm long.


(a) a compression testing machine;

(b) a 4.7 mm diameter steel rod with anhemispherical end;

(c) and a 120° steel vee block at least300 mm long.

(iii) The test method shall be as follows:

(a) condition the test specimens for at least1 hour at 23°C ± 2°C;

(b) insert the steel rod in the jaws of themoveable platen of the compressiontesting machine so that thehemispherical end protrudes at least15% of the nominal pipe diameter;

(c) (11/07) position the specimen in the veeblock and place directly below the steelrod, for twin-walled pipe the specimenshall be positioned firstly so that the rodstrikes on the corrugation or rib, andsecondly in the valley (where possible);

(d) set the machine to lower at a rate of5 mm/min;

(e) allow the rod to travel into the pipe adistance equal to 10% of the nominalinternal diameter of the pipe (T10 mm) oruntil the pipe wall is perforated. Whenthe outer skin of a twin wall pipe isperforated before 10% is attained, therod travel up to the point of failure shallbe recorded (Tf mm) and the rodallowed to travel to the inner wall. Therod travel shall be continued to a total of10% (ie T10 - Tf) or until completepenetration occurs.

(iv) For each test specimen: pipe size, reference,maximum load and rod travel shall berecorded.

14 Notwithstanding the requirements of sub-Clauses11, 12 and 13 of this Clause, variations in the testmethods specified therein shall be made where deemednecessary by the British Board of Agrément (orequivalent) following consultation with the manufacturerand in agreement with the Overseeing Organisation. Allsuch variations shall be recorded in the report.

Certification

15 Pipes and fittings shall have a current British Boardof Agrément Roads and Bridges Certificate (orequivalent) certifying the appropriate physicalproperties when tested in accordance with this Clause.

519 (05/01) Concrete Bagwork

1 (11/03) ST4 concrete in compliance withClause 2602 shall be used throughout. The concretefilling to the bags shall have a low workability with aslump of 25 mm.

2 The bags shall be hessian sand bags complyingwith BS 1214. The size of the bags shall be such thatwhen filled, the dimensions shall be 450 mm x 300 mmx 150 mm. The bags shall be placed in position andshaped to the profile shown on the Drawings by strikingwith a flat timber board until all faces are flat and alledges square.

3 The finished exposed faces of the bagwork shallnot be punctured or torn and no tucked ends shall bevisible.

4 Each concrete bag is to be spiked to the one belowand the bottom row spiked to the foundation with10 mm x 200 mm mild steel dowel bars. Where theconcrete bags have a concrete backing, alternate rowsof bags shall be spiked to the backing concrete with10 mm x 200 mm mild steel dowel bars at 45 degrees tothe horizontal with one dowel per bag in the row.




5 (11/03) Where bagwork forms a headwall, headwallfoundations are to be cast against the excavated faceand any overdig filled with ST4 concrete.

6 Formed concrete surfaces shall be to Class F1finish and unformed surfaces to Class U1 finish inaccordance with Clause 1708.

7 Where bagwork is provided to protectwatercourses, before placing the bags, the banks shallbe cut into horizontal steps to provide a suitablefoundation and shall be covered in geotextile to therequirements of Clause 609. The bottom course of bagsshall be at least 450 mm below the stream bed and allsucceeding courses shall be horizontal and all verticaljoints shall be staggered in alternate courses. Headersshall be placed at every third bag in alternate courses.

8 The bagwork shall be thoroughly soaked withwater upon completion of the construction to saturatethe hessian bags.

520 (05/01) The Cleaning of Existing DrainageSystems

1 Where stated in Appendix 5/1, the Contractor shallclean existing drainage systems in accordance with thisClause.

2 The Contractor shall take measures when clearingblocked drains to ensure that adjacent water courses orgroundwater via soakaways, will not be contaminated.Contamination includes mud or soil being washed orflushed into streams as well as other more obviouscontaminants including diesel fuel, oil and chemicals.

3 (11/03) Initial attempts to clear blocked drains priorto jetting, shall be undertaken by hand rodding and anydebris and silt removed by the operation shall beremoved off Site. The Contractor shall report anylocalised blockages that cannot be cleared by rodding tothe Overseeing Organisation.

4 (11/03) Where jetting is required in Appendix 5/1the procedures stated in Clause 521 shall be followed.

Cleaning of Gullies, Catchpits, Soakaways and OilSeparators

5 At each chamber all mud and vegetation in thevicinity of the chamber likely to impede the flow ofwater shall be removed. After lifting the cover orgrating the chamber shall be cleansed of all water,detritus, debris and silt, refilled with clean water to theoutlet level, and all covers and gratings replaced andevenly bedded.

6 (11/03) Cleaning of chambers shall be bymechanical means. The vehicle used to clean existingchambers shall be equipped with a 125 mm dia gulley

arm with boom jets, an exhauster with a minimumoutput of 5.95 cum/min and minimum 5455 litrescapacity. Sediment, detritus and liquor from thechamber shall not be permitted to discharge into theoutlet. This may be achieved either by plugging theoutlet during cleaning, or by simultaneous jetting andabstraction of liquor from the chamber using a tankerfitted with low pressure high volume water jets aroundthe boom.

7 Gullies and chambers not cleaned for whateverreason, blocked connections and broken or crackedcovers, gratings or frames shall be marked to aidsubsequent identification.

8 Oil separators shall be refilled withuncontaminated water following the cleaning operation.

9 (11/03) The Contractor shall dispose of all surpluswater, debris and arisings from the works off Site at alicensed tip.

Cleaning or Testing of Piped Drainage Systems andSubway Drainage Channels

10 (11/03) Routine cleaning or testing of piped drainagesystems and subway drainage channels shall be carriedout by rodding or low pressure high volume jetting inaccordance with Clause 521.

11 (11/03) The location of any obstruction that cannotbe removed by flushing shall be marked on the groundusing a wooden peg or other semi-permanent means andreported to the Overseeing Organisation using theRoutine Maintenance Manual System (RMMS)referencing system in Part 3, Chapter 3.7.

12 All covers which have been removed for cleaningoperations shall be replaced and evenly bedded.

13 The Contractor shall report any damage and defectsto the drainage system or components to the OverseeingOrganisation each day, or immediately if considered asafety hazard.

Cleaning Kerb or Channel Offlet Pipes

14 Where necessary all vegetation and debris shall beremoved from around metal kerb weirs and the coverlifted for cleaning.

15 Offlets shall be cleaned such that all silt and looseobstructions are removed from the pipe. This shall beachieved by rodding or by using lorry-mounted drainclearance equipment comprising combination pressurejetting with high air flow suction equipment. Thevehicle shall also be equipped with a hydraulically-powered grid lifter.

16 The Contractor shall ensure that each end of theofflet is free from vegetation or other obstructions




including any material expelled from the pipe. Wherethe invert of the outlet is below the invert of the ditch,the bottom of the ditch shall be excavated until theinvert of the pipe is exposed and the ditch invertregraded to facilitate flow from the outlet.

17 The location of any obstruction that cannot beremoved shall be marked on the ground using a woodenpeg or other semi-permanent means and reported to theOverseeing Organisation.

18 All covers lifted for cleaning operations shall bereplaced and evenly bedded.

Cleaning of Bridge Drainage Systems

19 Cleaning of bridge bearing shelves, subway sumps,grit chambers and other bridge drainage systems shallbe carried out by one of the following methods:

(i) vacuum/air suction having the ability toremove materials from depths of up to 9.0 mwith a suction facility capable of displacing55 m³/min of air at 95% vacuum;

(ii) (11/03) low pressure high volume jetting inaccordance with Clause 521;

(iii) sweeping.

20 All adjacent surfaces of the structure shall beprotected to prevent staining by arisings from thecleaning operation. All arisings shall be taken off Site.

21 The Contractor shall report to the OverseeingOrganisation any damage or defects to the bridgedrainage system.

521 (11/03) Low Pressure High Volume Jettingof Drainage Systems

1 Where stated in Appendix 5/1, the Contractor shallclean existing drainage systems in accordance with thisClause.

2 The drainage systems to be cleaned shall be asdetailed in the Appendix 5/1.

3 The pipe material of the drainage systems to becleaned shall be identified in Appendix 5/1. Where thematerial is unknown and cannot be verified by eithervisual inspection, without recourse to man-entry, orfrom drainage records, or damage to the pipeline is thesuspected cause of a blockage, cleaning shall proceedon the basis of use of the lowest pump pressure statedin Table 5/12.

4 Where the cleaning forms part of the pre-cleansingworks for the CCTV survey of drainage systems, theworks shall be detailed in Appendix 90/1 (see ModelContract Documents for CCTV Survey of HighwayDrainage, (MCHW 5.9.3).


Jetting of Piped Drainage Systems

5 Cleaning shall take place from downstream of theblockage in an upstream direction. The pipe shall beplugged below the jetting point to prevent contaminantsflowing to the watercourse. The cleaning shall takeplace from a chamber, although it may be necessary tomake a temporary excavation into the pipeline in somecircumstances.

6 Should the Contractor find that it is not possible tojet in an upstream direction, then the pipe shall beplugged below the blockage and the jetter then used to“back jet” to a suction hose.

TABLE 5/12: Maximum Recommended PumpPressures

Material Maximum pumppressure (bar/psi)

Unknown/structurally damaged 80/1200

Brick/masonry 100/1500

Plastics - Structural Wall 127/1900

Plastics - Solid Wall 127/1900

Concrete 340/5000

Clay 340/5000

7 The Contractor shall select a jethead that isappropriate for delivering the maximum jetting pressurefor the pipe material and also the minimum volume ofwater for the appropriate pipe diameter stated inTable 5/13.

8 The jet head shall be of a configuration such thatthe number and direction of jets are adequate to bedirected to the sides and soffit of the pipeline to preventdebris passing over the top of the jetting head.

Table 5/13: (11/06) Minimum Jetting Flow Rates

Pipe Diameter Minimum jetting flows

<230 mm 156 l/m

450 mm 270 l/m

900 mm 300 l/m

1600 mm 342 l/m

9 The Contractor shall provide suitable jettingequipment that shall include the provision of thefollowing:

(i) operation at a maximum rate of 850 l/min at150 bar/2250 psi;



(ii) liquid ring vacuum pump operating with airflows of 4000 m3 per hour, with a workingvacuum of not less than 90%;

(iii) a minimum of 20 m of 100 mm diametersuction hose for cleaning pipes up to300 mm diameter and 150 mm diametersuction hose for cleaning pipes of diametergreater than 300 mm;

(iv) minimum of 150 m of 25 mm or 38 mmdiameter jetting hose and a capability ofjetting up to 200 m;

(v) automatic and continuous water recycling;

(vi) silt, sand and rubble to be de-watered priorto discharge at licensed tip.

10 The Contractor shall ensure that no damage occursto the manhole chamber or pipeline during insertion ofthe jetting equipment.

11 (05/05) The jetting head shall be propelled throughor over the blockage and then the hose pulledbackwards enabling the force of the jet to break up theblockage material. The minimum force necessary topenetrate the blockage shall be used but the pumppressures should not exceed those stated in Table 5/12.

12 The hose shall be rewound at a rate of between100 mm and 200 mm per second.

13 There is a possibility that damage may occur tocertain pipe materials should the jetting head remainstationary thus the Contractor must ensure that thejetting head never remains stationary for more than60 seconds.

14 Perforated pipes and porous concrete pipescommonly occur in piped highway drainage systems.Where their presence is discovered during the course ofthe works, the Overseeing Organisation shall benotified immediately and the cleaning operationsuspended for that section of the works.

Cleaning of Linear Drainage Systems

15 Where possible the Contractor shall clearblockages in linear drainage channels and combinedkerb drainage units by rodding.

16 Where silt removal is necessitated, the use ofpressure jetting will result in the loss of pressurethrough the grating, slot or drainage holes together withthe escape of silt and debris, unless the apertures can betemporarily covered. The application of pressure shallbe regulated such that there is only sufficient to drivethe jetting head across the silt to access remote from thepoint of entry.

28FAmendment - May 2005

17 If necessary the jetting head shall be changed forone that can deliver the highest volume of water at lowpressure. The water pressure shall be sufficient toagitate the silt.

18 The nozzle shall be drawn back to the point ofentry at a rate of between 100 mm and 200 mm persecond.

Silt Removal

19 Suitable measures such as stanks or stoppers shallbe positioned downstream of the drainage system to becleaned to minimise the risk of sediment causingcontamination of watercourses or soakaways.

20 Wherever practical the Contractor shall useequipment to carry debris over a greater depth than oneatmosphere and with a capability to suck liquid.

21 All arisings from the cleaning process shall bedisposed of in an environmentally sensitive manner inaccordance with current legislation.

Health and Safety

22 The use of high pressure water can result in seriousinternal injuries that may not be apparent at the skinsurface.

23 The Contractor shall ensure that all hoses are freefrom damage and that the equipment is in full workingorder.

24 Where overhead electric cables are present, there isa potential danger from accidental strike by a jet ofwater.



508NI Gullies and Pipe Junctions

1 (05/06) Gullies shall be trapped, untrapped orsumpless as described in Appendix 5/1 and be inaccordance with HCD Drawing Numbers F13 and F14.All ST concrete referred to in this Clause shall complywith Clause 2602 unless otherwise described inAppendix 5/1.

2 Gullies shall be constructed so that no part of thespout or trap has a cross-sectional area less than 2/3rdthat of the outlet. The depth of water seal in trappedgullies shall be not less than 50 mm.

3 (05/05) Precast concrete gullies shall comply withBS 5911-6 and clay gullies with BS EN 295. In situconcrete gullies shall be as described in Appendix 5/1and constructed of ST4 concrete of 150 mm minimumthickness, using permanent or removable shuttering.Where in situ concrete gullies are formed withpermanent shuttering, such shuttering shall have acurrent British Board of Agrément Roads and BridgesCertificate. Precast rectangular section gullies shall beas described in Appendix 5/1.

4 Gully gratings, kerb type gully covers and framesshall comply with BS EN 124 and the following and shallbe of the classes and sizes described in Appendix 5/1.

5 (05/01) The upper surface of gully gratings shall beflat except where otherwise described in Appendix 5/1.Slots in gratings or between gratings and frames shallnot be orientated parallel to the direction of trafficexcept where the slots are less than 150 mm long or lessthan 20 mm wide. Minimum waterway areas shall be asspecified in Appendix 5/1. Unless otherwise specifiedin Appendix 5/1, all gratings and frames shall besupplied in a fine cast (uncoated) condition. Where acoating is specified in Appendix 5/1, the coating shallonly be applied when the surfaces of the casting areclean, free from rust and dry. Gully gratings shall belaid parallel to and 6 mm below the finished roadsurface. Hinged gratings shall be orientated to close inthe direction of traffic flow. Frames shall be bedded onmortar complying with sub-Clause 507.16. Brickworkshall comply with sub-Clause 507.3.

6 (05/04) Backfilling to precast gullies shall be carriedout up to sub-formation level with general fill materialClass 1, as described in Table 6/1 compacted incompliance with Clause 612. Where mechanicalcompaction is impracticable, the backfilling shall be in

NATIONAL ALTERATIONS OF THE OVERSEEINGORGANISATION OF NORTHERN IRELAND

ST2 concrete. The remainder of backfilling aroundgully shall be strength class C8/10 or ST2 concrete.

7 (11/03) Gully connection pipes shall be eitherflexible or rigid not exceeding 0.7 m in length withflexible joints for a distance of 2 m from the gully andshall be in accordance with sub-Clause 507.17 whenentering chambers. Junction pipes shall bemanufactured of the same type and class of material asthe remainder of the pipes in the run. Junction pipeswhich are laid but not immediately connected, shall befitted with temporary stoppers or seals and the positionof all such junctions shall be clearly defined by meansof stakes or tracing wires properly marked or labelled.Saddles may be used to form junctions only wherepermitted in Appendix 5/1. No internal projectionsgreater than 5 mm will be permitted. Saddles forasbestos cement and plastics pipes shall be installed inaccordance with the manufacturer’s recommendations.Saddles with clay pipes shall be jointed with mortardesignation (i) complying with Clause 2404, excludinglime. Saddles and pipes shall be surrounded with ST2concrete.

8 (05/01) Where the adjustment or replacement ofexisting frames and gratings is required, the units shallbe taken up and re-fixed or removed and replaced withnew units complying with sub-Clauses 4 and 5 of thisClause, or as described in Appendix 5/1. On taking upor removal of the unit, any concrete or mortar beddingshall be broken out and the surface prepared. Whereexisting frames and covers or gratings are to beadjusted, the Contractor shall take up the unit and cleanit for re-use. The adjusted or replaced units shall be laidat a level, unless otherwise described in Appendix 5/1,6 mm below the adjoining road surface on a mortar bedcomplying with sub-Clause 507.16. The finishedthickness of the mortar bed shall be between 10 mmand 25 mm. Where required in Appendix 5/1, coversand gratings shall be bedded using a proprietary quicksetting high strength mortar. Details of such mortarshall be to the approval of the Overseeing Organisation.Any additional adjustment shall be made by modifyingthe brickwork in compliance with sub-Clause 507.3 orby using a frame of suitable depth. On completion ofthe works, each grating shall be lifted and the frame andseating cleaned.

N1FAmendment - May 2006

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