working load

7/27/2019 Working Load

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ExpoStation&OverrunTunnel

Contract922DTL3

MethodStatementforBoredPileWorkingLoadTestRev.

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i.Provide 1600mminternal diametercasingwith8mmmthickand the debondinglengthwillbeprovideduptothedesignminimum300mmbelowcutofflevel.

ii.The casing will be wrapped all round with proposed Bituthene 3000 debonding

membranethatprovidessmoothsurfacethatcreatesadebondingeffectforthepile.iii. Inadditionalmeasures toprevent theinflow ofconcreteinto theannular space during

concreteplacing,2layersof1200mmx25mmthickpolystyreneplugwillbeinstalledat500mmabovethebottomofthedebondingcasing.Thepolystyrenewillbecontinuouslywrappedwiththedebondingmembranetopreventanydamagetothepolystyreneduringdebondingcasinginstallation.

Thedebondingcasingdetailandtheproposeddebondingmaterial,Bituthene3000productdetailandspecificationcanbereferredinAppendixD.

5.2.2.InstallationofDebondingCasing

Thesequencesfordebondingcasinginstallationareasfollows;

i. Installed 1800mm diameter outer temporary casing in accordance with the earlierexplainedsection5.1.

ii.Preboringof1800mmdiameterboreholewillcommencedwithfromthegroundlevelandstopatthedesignC.O.Llevel(81.025mRL)

iii. Installedthe1600mminternaldiameterdebondingcasinguptothefinallevelof1800mmdiameterpreboreholewhichwasdoneinstep.(ii).Theverticalityandpositioningofthedebondingcasingismaintainedduringtheinstallationprocessbyinstallationof4nosof50mmspacerbarwhichweldedtothesideofthedebondingcasingatevery3minterval.DetailscanbereferredinAppendixC.

iv.Uponthedebondingcasingtoereachtothebottomofthe1800mmpreboredhole,thedebondingcasingwillbegraduallypresseddownbyusingboringrigskellybaruntilthetoe of the debonding casing penetrate at least 300mm below the Pile Cut OffLevel(81.025mRL).

v.Surveyorwillcheckthepositionandverticalityofinnerdebondingcasingafterreachingtorequiredlevel.Adjustthepositionandverticalityofthecasingwithintheannularspacebetweenouterandinnercasingifnecessary.

vi.The1600mmdiameterdebondingcasingwillbesecurelyweldedontothe1800mmIDoutertemporarycasing.

vii. Bentoniteslurrywillbefilledimmediatelyifencounteredthegroundwaterlevelintheprocessofabovestage.itovi.Otherwisebentonitewillbefilledintotheboredholeatthis

stagetillreachgroundlevel.viii.Changethedrillingtoolsfrom1800mmdiameterto1600mmdiameterandcontinuebore

totherequireddesigntoelevel.

ix.TheillustratedsequenceforthedebondingcasinginstallationcanbereferredinAppendixC.


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Contract922DTL3


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Test PileRef

App roximate

Casing top level

(mRL)

C.O.L

(mRL)

Debonding

Casing length

(m)

Debonding

Casing Size(ID)

(mm)

Outer Casing

Size(ID)

(mm)

Remarks

(a) (b) (c)=(a)-(b)+0.3

S30 106.025 81.025 25.3 1600 1800

6. KentledgeLoadTestMethodology

The methodology for the preliminary compression bored pile test construction and installationcoversonthefollowing;

A. ListofPlantandEquipmentforKentledgeSettingUp

B. MethodologyofKentledgeAssemblyandSettingUp

C. TestingEquipment

A. ListofPlantandEquipmentforKentledgeSettingUp

TheplantandequipmenttobedeployedforKentledgesettingUpWorksarelistedintheTable2.

No EquipmentDescription Capacity Units

1 HydraulicCrawlerCrane 100tons 1

2 Excavator 7m 1

3 WeldingMachine 500Amp 1

4 GeneratorSet 50kVA 1

5 HydraulicJack 1000tons 2

6 LoadCell 1000tons 2

7 DialGauge 15hp 2

8 DumpyLevel SokkiaorSimilar 1

9TelltaleRod(Extenometer)

C/WDialGauge10tons 1set

10 HydraulicPump Enerpac 1set

11 TestBlock 2.4~4tonsRefertoKentledgeSet

Updrawingdetails

12 MainGirderBeam 2000tons 1set

13 SecondaryBeam 2000tons 1set

14 BearingPlate 100mmthick 2pcs

Table2.ListofPlantandMachineriesforKentledgeSettingUpworks.

Thecalibrationcertificatesformonitoringapparatuswillbesubmittedinseparatesubmission.


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Contract922DTL3


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B. MethodologyofKentledgeAssemblyandSettingUp

Kentledgetestpilemethodisthetypeoftestthatmostwidelyusedincompressionloadtesting. In this method, the concrete blocks are stacked upwards with the supports of

secondarybeamtoformsareactiondeadweight.

TheKentledgesystemconsistsof:

i. Concrete Blocks; (support casing where necessary or applicable will beaddressinseparatesubmission)

ii. ASectionofBeamssupportingtheConcreteBlocks;iii. MainGirderstotransfertheloadtothehydraulicjack;iv. Requirednumberofhydraulicjacktotransfertheloadtothetestpile;v. Requiredsetofinstrumentformeasuringthepressureagainstthetestpile;vi. (PressureGaugewillbeusedtoindicatetheloadappliedtojacks.The

actualappliedloadshallbemeasuredfromLoadCells)vii. 1setofinstrumentformeasuringthesettlementofthetestpile(DumpyLevel

with2BenchMarksand/or2DialGauges).

TheproposedKentledgesettingupforPreliminaryCompressionTestPileisshowninFigure1andthelayoutdrawingforWorkingLoadtestPilecanbereferredinAppendixE.

Figure1.TypicalKentledgeSettingup

Theconcreteblocksshallprovidethenecessaryreactionrequiredinthetest.Overallconcreteblocks shallbeprovidedupto110%ofanticipatedTestLoad.MainGirdershallbealignedtocentreofgravityofconcreteblockstomaintainsafeandstablesetup.The secondary beams will be arranged overlay on top of the main girder beamperpendicularly.ThedetailsandcalculationfortheMainGirderandSecondarybeamcanbereferredinAppendixE.KentledgefoundationandsupportdesignwillbebasedonPE'sendorsementdesign,hardcore fillingorconcreteplatformwillbe lay aboveground toprovide additional

working load

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