設計匯編9外文翻譯

[11]xiu-jie.Discussaboutqualitycontrolofboredpilesconstruction.Journalofjiaxingcollege.2002Pickto:combinedwithboredpilesinactualconstructionqualityproblem,putforwardthecorrespondingpreventionmeasures,thispaperdiscussesthefillingpileconstructionqualitycontrolpoints.:boredpiles;Construction;Quality.libraryclassificationTU753.Boredpilesisdirectlyinthedesignofpilelocatedinopenhole,thenputinholeandreinforcingcageandpourconcreteintoapilefoundation.ThiskindofpilefoundationinBridgesandotherprojects,themostbasicstructureofboredpiles.Suchasthreebridge,rainbowbridge,TaiShiQiaoandsoon.Thispapersummarizestheboredpilesintheactualconstructionoftenpronetoqualitycommonfaultandpreventionandcontrolmeasuresareputforward,andhopeforsomeofotherboredpilesconstructiontechnologyisofcertainreferencevaluetotheproblem.OneofthecommonqualitycommonfaultofboredInviewofthecast-in-cepileinpracticalengineeringsitepreparation,drilling,holecleaningtopouringunderwaterconcreteandsooneachlink,correspondingtothequalitycommonfault:offset,superthick,concretesegregationofdregdepositedatthebottomofthebore,pilebodyconcrete plete(includingsandwich,necking,exposureofpile,concreteisweak,loose,piletopconcretereinforcingcageup-floating),etc.Theexistenceoftheseproblems,itisleadtotheunderlyingcausesoftheaccident.Soyoumustcontroltheoccurrenceoftheseproblemsasthefocusintheconstructionprocessofboredpiles.2preventionandcontrol2.1precisepositioning:spudforpreciselofting,linersembeddingposition,thestrictcontrolofnepositioningaccuracyofpile.Forpileverticaldegreeofcontrol,asaresultoflinersforthedrilldowndirectionhasaguidingrole,sotoprotectthecylinderupanddowntothevertical.Thefirstdrillholepositionandverticalitytogivespecialattentionto,todothis,mustuseupperandlowertwotic-tac-toeframe,atthesametimeintheprocessofdrillingshouldbethesettlementanddiscementobservationtform,atanytimetocorrect.Drillingisdevolvedreinforcingcage,tobereinforcingcagepositionaccuray,verticaldrop,coverthicknessmeetthedesignrequirements,usingwheeltypeconcreteblockisagoodwaytosolvethisproblem.Dealwithreinforcingcagehooksarefixedatthesametime,inordertosolvetheproblemofsteelreinmentcagefloating.2.StrictlycontroltheholebottomsedimentBecauseofdrilledpileallowablebearingcapacityandthecoefficientbym0valuerelationshipisgreat,clearbottombetterthanallowablebearingcapacityof3~4timesofpoor,soshouldstrictlydonotgreaterthanthethicknessofdesignrulesofdregdepositedatthebottomofthehole,toachievethis,holecleaningmustbethoroughly,adoptingtwotimesofblackhole(i.e.,loweringsteelreinmentcageandagainaftercatheterholecleaning),controltheslurryconcentration.Lastsedimentdetectionconcretepouringshouldtrytoshortenthetimeinterval,holecleaningagainifnecessary.Controlthesedimentthicknessforendbearingpilerock-socketedpileisparticularlyimportant,andmustbestrictlymeetthedesignrequirements,otherwisewillleadtounevensettlement,andendangerthesafetyoftheupperstructure.2.3keycontrolunderwaterconcretepouringprocess,ensurethequalityofpilebodyConstructionprocessofboredpilesoftheunderwaterconcreteperfusionislonger,hightechnicalrequirements,andalargeproportionofdrillingpilequalitycommonfault,areavailableonthislink,sostrictcontrolofunderwaterconcretepouringprocesstoensurethequalityofboredpileiscritical.Thespecificpracticesareasfollows:guaranteetheconcreteeffectivehead,intheprocessofunderwaterconcreteperfusion,funnelbottomholeshouldbehigherthanthatofWellswater4~6meters(whenthepileheadhighinthewaterhole,higherthanthatoffunnelbottomofpiletop4~6meters),especiallyinthelast10meters,concretecastingmustbestrictlycontrolledandmeetthetechniquerequirement,inordertosatisfythepipeinsideconcretespreadtotheoutsideofthetubeandthetubeoutsidethetopofthefirstconcretethesuperpressurerequired.shouldincreasethenumberofthefirstbucketofconcrete.Inpracticethenumberofthefirstbucketofconcreteshouldbeabletomakethecatheterembedmentdepthin1metersadvisable,ifbecauseofthedepthofembedmentistoosmall,canmaketheafterpouringtheconcreteisnottopofthewholelayerdownfirstpouringconcrete,butnearandsuccessivelyperfusionlayerbetweenclampsmudandbrokenpile.whenpouringunderwaterconcrete,afterthefirstbatchofperfusionconcreteshouldalwaysbeinthetopofeachbatchofconcretepouring,andcontactwithwaterormud,eafterpouringtheconcreteofthewaterprooflayer,toensurethequalityofafterpouringtheconcrete,andthereforerequiresthefirstconcretefromperfusiontoperfusioniscompleted,shouldalwayskeepthenecessarysticityandfluidity(aninitialsetting).Soyoumusttrytoshortenthefillingtime,maketheperfusionworktobedonebeforethefirstconcreteinitialsetting.Todothis,firstchoosecloseto,arelativelyflattransportroutes.Toconnectdifferentoperatingprocedures,tolargepilediameteranddepthoflongpile,heprocessofconcretepouring,oftenshoulddetectthedepthoftheconcretesurfaceandthebottomofthecatheter,keepthecatheterintheconcreteembedmentdepthismorethan2metres,otherwise,thenewconcretemaybreakthroughthefirstconcreteperfusion,taketotheconcrete,theconcreteandthesludgebywashingaroundintothepile,andformasandwich,brokenpile.Ofcourse,inordertopreventthetubeconcreteascensionisdifficult,evencan'tpullitout,causeaccidentburiedpipes,catheterumembedmentdepthshouldnotbegreaterthan6meters.underwaterconcreteshallbecontinuouscasting,forbiddeninterliningandfault.,ofcourse,maybeunexpectedemergenciesinconstructionprocess,suchassuddenblackouts,machinemalfunction,theconcretepouringbreakaccident.Atthispointintheverylikelyinterliningandbrokenpile,shouldactivelytakemeasurestoavoidloss.Ifyouneedtocastcanbetakentouseaircompressortoholecleaning,cleanthesedimentandtheupperlooseconcreteinhole,thenpouring,aftershoulddetecttheintegrityofthewholerootpile,toensurethequalityofcasting.concretepouringheightshouldbehigherthanactualdesignelevationabove50cm,shouldstepupthefinalpouringtyatthesametime,maketheholeofalllaitanceoverflow,ensurethecompactnessofconcretepilehead.7)rock-socketedpilessocketeddepthmustreachthedesigndepth,forthis,thesupervisionmustbestrictlycontrolledintheconstruction.Practicecanuserigidrodoraheavyhammerlineandcombinedwiththegeologicalreportforsure.Requirements,suchasdesignofstratathathavetotakethestonesamplesforidentification,todeterminewhethertoreachthedesignrequirementsoftherockface.Rock-socketedpilesuchasdesignofpilestrengthwhenwehaverequirementsforshallowcover(especiallythepierconstructionofpileatthesametimeintheexposedarea),shouldbecontrolledsteellinersoftheembedmentdepth,steellinerswiththetillthebottomofthehole.3BoredpilesusedasthefoundationofthelargestructuressuchasBridges,docks,soitsqualitymatter,itisrelatedtonationalandpeople'slifeandpropertysafety.Thispapermentionedbeforeafewbridgeinexpertevaluationthroughthequalitycheckandaccept.Soweshouldaccumulateexperienceinactualengineering,improvethetechnology,strengthenthecontrol,umlimittopreventqualityaccidents. 要:結合鉆孔灌注樁實際施工中容易出現(xiàn)的質(zhì)量問題,提出了相應的防治措施,論述了灌注樁的施工質(zhì)量控制要點。:鉆孔灌注樁;施工;質(zhì)量。號:TU753.1節(jié),相應容易產(chǎn)生的質(zhì)量通病有:偏位、沉渣超厚、混凝土離析、樁身混凝22.12.2嚴格控制沉渣厚度m0值關系極大,清底較好的可比差的提高容許承載力3～4倍,所以應嚴格做到沉渣厚度不大于設計規(guī)定,要達到這一點,清孔必須徹底,采用兩次清孔(即下放鋼筋籠及導管后再次進行清孔),控2.34～64～610126澆注,過后應檢測其整根樁的完,以保證澆注質(zhì)量的優(yōu)良。50有要求時,(特別是碼頭施工中對于覆蓋較淺同時處于無遮掩海域的樁),應控3[12]Longandlight——《Bridgedesign&engineeringClosureofthemainspanontheSundoyaBridgeinNorwayisexpectedtotakeceinthefirstweekafterEaster.Thisgracefulcrossing,thesecondlongestofitstypeintheworld,isbeingbuiltinsituusinghighperformanceconcreteSundoyaBridgeissituatedinoneofNorway'smostscenicareas,only100kmsouthoftheArcticCircle.The538m-longbridgespansSundet,andwhenitiscompletewillprovideaferry-roadconnectionbetweenSundoyaandthe.Itislocatedsome35kmwestofthecityofMosjoen,closetohighway78betweenMosjoenandSandnessjoen.ItwillbethesecondlargebridgeprojectconnectingAlstenoyatothe,comingmorethan12yearsaftertheHelgelandBridgewasopened.Theregionisnostrangertoworld-recordscalebridges?theHelgelandBridge's425mlongmainspanwasthelongestcable-stayedspanintheworldwhenitopenedin1992.SundoyaBridgeisdividedintothreespans;ithasamainspanof298mandtwosidespansof120m.Themainspanwillbethesecondlongestspanintheworldforacontinuouspost-tensionedcastinceboxsectionconcretebridge.Intermsofitsdesign,consultantDrIngAas-JakobsenhasfollowedasimilarapproachtothattakenfortheRaftsundetBridge,openedin1998,towhichtheSundoyaBridgewillalmostbeatwin.Thetwobridgeshaveidenticalmainspans,butRaftsundethasfourspansasopposedtoSundoya'sthree.ContractorASAnlegg,whichispartofthejointventurebuildingSundoya,wasalsothecontractorontheRaftsundetBridge,andarchitectBoarchArkitekterhasalsoworkedonthetwoInJanuary2001thejointventureAFSundoybruawonthecontractfromStatensVegvesentobuildtheSundoyaBridge.ThisjointventureconsistedofthecontractorsReinerAnleggandNCCConstruction.Highperformanceconcreteiscentraltothedesignofthebridge?bothnormalweightHPCandlightweightHPC.Normalweightconcrete,atapproximay2500kg/m3,isusedforthe120msidespans,whilelightweightconcrete,whichweighsinatabout1970kg/m3,isusedforconstructionofthe298mmainspan.Thisenablesconstructiontoproceedusingthebalancedcantilevermethod.LocalrockfromNorwayisusedastheaggregateforthenormalweightconcrete,butthelightweightconcreterequiredanimportedsolution.NormallytheaggregateusedforlightweightconcreteinEuropeisexpandedclayorshale,butthismaterialhashighlevelsofabsorptionandforthisreason,regulationspreventsuchconcretefrombeingpumped.Inordertoaddressthis,thecontractoradoptedasimilarsolutiontothatusedonRaftsundetBridge?importingStaliteaggregatefromSouthCarolinaintheUSA.Staliteisproducedthroughthermalexpansionofhighqualityslate,andresultsinalightweightaggregatethatgivesconcreteofveryhighstrengthatlowunitweights.Itslowabsorptionofapproximay6%andhighparticlestrengtharetwoofthefactorsthatallowStalitetoachievehighstrengthconcreteinexcessof82.7MPa,themanufacturersays.Thebondandcompatibilityoftheaggregatewithcementpastereducemicro-crackingandenhancedurability,anditslowabsorptionmakesiteasytomixandpump.AccordingtoAFSundoybruaqualitymanagerJan-EirikNilsskog,thismaterialhasgivenaverygoodresult.Itproducesconcretethatiseasytopourintotheformworkanditgivesagoodsurfacefinish,hesays.Itisbeingpumpedsome120malongthebridgedecktotheconcretingposition.Concreteisproducedbya ntlocatedonly1kmfromthebridgesite.Constantmonitoringoftheconcreteweightisnecessarytoensurethatthecantileversareproperlybalanced.Thisistestedforeachpour.TheprojectbeganinJanuary2001atAkerVerdalwiththeproductionofcaissonsforthepierbases.InMay2001thetwocaissonsweretowed500kmnorthtothebridgesite.ThebridgeisbeingpouredinsituusingspecialconstructionequipmentdevelopedbyNRS.Thecycleforconstructionofeach5mwidebridgesegmentisaweek,andtwounitsarebeingusedontheSundoyaBridge.TheseparticularunitswerebuiltforASAnleggtouseontheVaroddenBridgeinKristiansandinNorway,andtheyhavealsobeenusedbythesamecontractorontheRafsundetBridge.ThedesignofthecentralpartofthemainspanofthebridgeisbasedontheuseoflightweightconcreteLC60whileotherpartsofthestructureusethemorestandardtypeC65.Becauseoftheaggressivemarineenvironment,thequalityoftheconcretemustbeparticularlygood.Thestructureisasinglecell,prestressedrectangularboxgirder,largelybuiltusingthetravellingformworksystemfromNRS.Theboxwidthis7manditsdepthvariesfrom3matthecentreofthespanto14.5moverthepiers.Closetotheabutments,concreteofqualityC25willbeusedinsidetheboxgirderasballast.Inaddition,thedesignershaveincludedthenecessaryelementsinsidetheboxgirderinordertoallowthepossibleadditionofpost-tensioningcablesinthefuture.Thelong-termbehaviourofsuchlargespansisnotfullyknown,sothepossibilitythatthemainspanmaysagovertimehastobetakenintoaccount.Thewidthoftheroadisaconstant7.5mfromthebarrierononesidetothatontheother,andthetotalwidthofthebridgeissome10.3m.Thereisa2mwidefootwayincludedinthewidthofthestructure.Thepiershaftisformedwithtwinlegs,whicharehollowinside.Thepiershaftsincorporatepermanentprestressingcablesandtheyhaveaconstantwallthicknessandawidththatvariesparabolicallyovertheirheight.Temporarytie-downpiersareusedtoconstructthebridge-theyarelocated35mintoeach120m-longsidespanfromthemainpiers.EachconsistsofanI-shapedshaft,whichistieddowntothegroundusingrockanchorsandconnectedtotheboxgirderbymeansofprestressingcables.Thepurposeofthesestructuralelementsistosupportthecantileverandpreventrotationinstrongwinds.Oncethebridgesuperstructureiscompleteandthemainpierprestressingisfullytensioned,thetemporarytie-downpierswillberemovedpiecebypiece.Thelocationofthebridge,onlyabout100kmsouthoftheArcticCircle,hasmeantthatspecialmeasureshavetobeintroducedtoallowconstructionworktocontinueallyearround.Apartfromtheobviousneedtoprovidesitelightingformuchofthewintertime,thechallengeofconcretingintemperatureswhichcanbeaslowas0Chastobe e.Hotconcreteisproducedforthebridge?sometimesupto30Candtheformworkhastobeinsulatedtokeeptheconcretewarm.ElectricheatingcablesarealsousedontheendofthepreviouspourtowarmuptheconcretebeforeConstructionofthenewbridgebeganinJanuary2000andisexpectedtobecompleteinSeptemberthisyear.TheconstructionofthecantileverstartedinsummerlastyearandisduetobefinishedinApril.When