地下室设计深基坑中英文对照外文翻译文献.docx
- 文档编号:6578819
- 上传时间:2023-01-08
- 格式:DOCX
- 页数:4
- 大小:19.03KB
地下室设计深基坑中英文对照外文翻译文献.docx
《地下室设计深基坑中英文对照外文翻译文献.docx》由会员分享,可在线阅读,更多相关《地下室设计深基坑中英文对照外文翻译文献.docx(4页珍藏版)》请在冰豆网上搜索。
地下室设计深基坑中英文对照外文翻译文献
地下室设计深基坑中英文对照外文翻译文献
中英文对照外文翻译 (文档含英文原文和中文翻译) DeepExcavations ABSTRACT:
Allmajortopicsinthedesignofin-situretainingsystemsfordeepexcavationsinurbanareasareoutlined.Typeofwall,water relatedproblemsandwaterpressures,lateralearthpressures,typeofsupport,solutiontoearthretainingwalls,typesoffailure,internalandexternalstabilityproblems. KEYWORDS:
deepexcavation;retainingwall;earthpressure; INTRODUCTION Numbersofdeepexcavationpitsincitycentersareincreasingeveryyear.Buildings,streetssurroundingexcavationlocationsanddesignofverydeepbasementsmakeexcavationsformidableprojects.Thischapterhasbeenorganizedinsuchawaythatsubjectsrelatedtodeepexcavationprojectsaresummarizedinseveralsectionsintheorderofdesignroutine.Thesearetypesofin-situwalls,waterpressuresandwaterrelatedproblems.Earthpressuresincohesionlessandcohesivesoilsarepresentedintwodifferentcategories.Groundanchors,strutsandnailsassupportingelementsareexplained.Anchorsaregivenmoreemphasiscomparedtoothersduetowidespreaduseobservedintherecentyears.Stabilityofretainingsystemsarediscussedas internalandexternalstability.Solutionofwallsforshears,moments,displacementsandsupportreactionsunderearthandwaterpressuresareobtainedmakinguseofdifferentmethodsofanalysis.Apilewallsupportedbyanchorsissolvedbythreemethodsandtheresultsarecompared.Typeofwallfailures,observedwallmovementsandinstrumentationofdeepexcavationprojectsaresummarized. 1.TYPESOFEARTHRETAININGWALLS Introduction Morethanseveraltypesofin-situwallsareusedtosupportexcavations.Thecriteriafortheselectionoftypeofwallaresizeofexcavation,groundconditions,groundwaterlevel,verticalandhorizontaldisplacementsofadjacentgroundandlimitationsofvariousstructures,availabilityofconstruction,cost,speedofworkandothers.Oneofthemaindecisionsisthewater-tightnessofwall.Thefollowingtypesofin-situwallswillbesummarizedbelow; 1.Bracedwalls,soldierpileandlaggingwalls2.Sheet-pilingorsheetpilewalls 3.Pilewalls(contiguous,secant) 4.Diaphragmwallsorslurrytrenchwalls 5.Reinforcedconcrete(cast-in-situorprefabricated)retainingwalls 6.Soilnailwalls 7.Cofferdams 8.Jet-groutanddeepmixedwalls 9.Top-downconstruction 10.Partialexcavationorislandmethod BracedWalls Excavationproceedsstepbystepafterplacementofsoldierpilesorsocalledkingpostsaroundtheexcavationatabout2to3mintervals.These maybesteelH,IorWFsections.Railsectionsandtimberarealsoused.Ateachlevelhorizontalwalingbeamsandsupportingelements(struts,anchors, nails)areconstructed.Soldierpilesaredrivenorcommonlyplacedinboredholesinurbanareas,andtimberlaggingisplacedbetweensoldierpilesduringtheexcavation.Variousdetailsofplacementoflaggingareavailable,however,precastunits,in-situconcreteorshotcretemayalsobeusedasalternativetotimber.Dependingongroundconditionsnolaggingmaybeprovidedinrelativelyshallowpits. Historicallybracedwallsarestrutsupported.Theyhadbeenusedextensivelybeforethegroundanchortechnologywasdevelopedin1970s.Soilswithsomecohesionandwithoutwatertableareusuallysuitableforthis typeofconstructionordewateringisaccompaniedifrequiredandallowed.Strutsupportiscommonlypreferredinnarrowexcavationsforpipelayingorsimilarworksbutalsousedindeepandlargeexcavations(SeeFig).Groundanchorsupportisincreasinglyusedandpreferredduetoaccessforconstructionworksandmachinery.Walingbeamsmaybeusedoranchorsmaybeplaceddirectlyonsoldierpileswithoutanybeams. Sheet-pilingorSheetPileWalls Sheetpileisathinsteelsection(7-30mmthick)400-500mmwide.ItismanufacturedindifferentlengthsandshapeslikeU,Zandstraightlinesections(Fig.).Thereareinterlockingwatertightgroovesatthesides,andtheyaredrivenintosoilbyhammeringorvibrating.Theiruseisoften restrictedinurbanizedareasduetoenvironmentalproblemslikenoiseandvibrations.Newgenerationhammersgenerateminimumvibrationand disturbance,andstaticpushingofsectionshavebeenrecentlypossible.Insoftgroundseveralsectionsmaybedrivenusingatemplate.Theendproductisawatertightsteelwallinsoil.Oneside(inner)ofwallisexcavatedstepbystepandsupportisgivenbystrutsoranchor.Walingbeams(walers)arefrequentlyused.Theyareusuallyconstructedinwaterbearingsoils. Steelsheetpilesarethemostcommonbutsometimesreinforcedconcreteprecastsheetpilesectionsarepreferredinsoftsoilsifdrivingdifficultiesarenotexpected.Steelpilesmayalsoencounterdrivingdifficultiesinverydense,stiffsoilsorinsoilswithboulders.Jettingmaybe accompaniedduringtheprocesstoeasepenetration.Steelsheetpilesectionsusedinsuchdifficultdrivingconditionsareselectedaccordingtothedrivingresistanceratherthanthedesignmomentsintheproject.Anotherfrequently facedproblemistheflawsininterlockingduringdrivingwhichresultinleakagesunderwatertable.Sheetpilewallsarecommonlyusedfortemporarypurposesbutpermanentcasesarealsoabundant.Intemporary workssectionsareextractedaftertheirserviceisover,andtheyarereusedaftermaintenance.Thisprocessmaynotbesuitableindenseurbanenvironment. PileWalls In-situpileretainingwallsareverypopularduetotheiravailabilityandpracticability.Therearedifferenttypesofpilewalls(Fig.).Incontiguous(intermittent)boredpileconstruction,spacingbetweenthepilesisgreater
thanthediameterofpiles.Spacingisdecidedbasedontypeofsoilandlevelofdesignmomentsbutitshouldnotbetoolarge,otherwisepiecesoflumpsetc.dropandextraprecautionsareneeded.Cohesivesoilsorsoilshavingsomecohesionaresuitable.Nowatertableshouldbepresent.Acceptableamountofwateriscollectedatthebaseandpumpedout.Commondiametersare,,m.Walingbeams(usuallycalled?
breastingbeams)areTangentpileswithgroutinginbetweenareusedwhensecantpilingordiaphragmwallingequipmentisnotavailable(incaseswheregroundwaterexists).Poorworkmanshipcreatessignificantproblems. Secantboredpilewallsareformedbykeepingspacingofpileslessthandiameter(S Thereisalsoneedforplacefortheplant.Itmaybeconstructed“hard-hard”aswellas“soft-hard”.“Soft”concretepilecontainslowcementcontent andsomebentonite.Primaryunreinforcedpilesareconstructedfirstandthen reinforcedsecondarypilesareformedbycuttingtheprimarypiles.Pile constructionmethodsmayvaryindifferentcountriesforalltypeofpilewallslikefullcasingsupport,bentonitesupport,continuousflightauger(CFA)etc. mostlyreinforcedconcretebutsheetpilesectionsorsteelbeamsarealsoused. DiaphragmWalls Diaphragmwallprovidesstructuralsupportandwatertightness.Itisaclassicaltechniqueformanydeepexcavationprojects,largecivilengineering works,undergroundcarparks,metropitsetc.especiallyunderwatertable.Thesereinforcedconcretediaphragm(continuous)wallsarealsocalledslurrytrenchwallsduetothereferencegiventotheconstructiontechniquewhere excavationofwallismadepossiblebyfillingandkeepingthewallcavityfullwithbentonite-watermixtureduringexcavationtopreventcollapseoftheexcavatedverticalsurfaces.Wallthicknessvariesbetweenmandm. Thewallisconstructedpanelbypanelinfulllengthsare2mto10m.Shortlengths(m)areselectedinunstablesoilsorunderveryhighsurcharges.Nowadaysdepthofpanelswaterstopsexceeded100m, excavationdepthsexceeded50m.DifferentpanelshapesotherthantheconventionalstraightsectionlikeT,L,H,Y,+arepossibletoformandusedforspecialpurposes.Panelexcavationismadebycableorkellysupported bucketsandbyarecentdesigncalled?
cutteror?
hydrofraisewhichisapairofhydraulicallyoperatedrotatingdisksprovidedwithhardcuttingtools.Excavationinrockispossible.Slurrywalltechniqueisaspecialized techniqueandapartfromthebucketortheframecarryingthecutterequipmentlikecrawlercrane,pumps,tanks,desandingequipment,airlifts,screens,cyclones,silos,mixers,extractorareneeded.Tremieconcreteis placedintheslurrystartingfromthebottomafterloweringreinforcement cages.Jointbetweenthepanelsisasignificantdetailinwaterbearingsoilsandsteelpipe,H-beamorwaterstopsareused. ReinforcedConcreteRetainingWallsExcavationinStagesItisacommontypeofstagedexcavationwallusuallysupportedbygroundanchors.Soilswithsomecohesionaresuitablebecauseeachstageisfirstexcavatedbeforeformworkandconcreteplacement.Nowatertableorappreciableamountofwatershouldbepresent.Sometimesmicropilesupportisgivenifrequiredduetoexpectedcave-ins. SoilNailWalls Similartothemethodaboveexcavationismadestepbystep(to2mhigh).Shotcreteiscommonforfacingandwiremeshisused.Softfacingisalsopossiblemakinguseofgeotextiles.Holeisdrilled,ordinarysteelbarsarelowered,andgroutisplacedwithoutanypressure.Soilshouldbesomewhatcohesiveandnowatertableorsignificantwaterflowshouldbepresent. Cofferdams Cofferdamisatemporaryearthretainingstructuretobeabletomakeexcavationforconstructionactivities.Itisusuallypreferredinthecoastaland seaenvironmentlikebridgepiersanda
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 地下室 设计 基坑 中英文 对照 外文 翻译 文献