毕业设计文献翻译.docx

毕业设计文献翻译.docx

《毕业设计文献翻译.docx》由会员分享，可在线阅读，更多相关《毕业设计文献翻译.docx（12页珍藏版）》请在冰豆网上搜索。

毕业设计文献翻译

本科毕业设计（论文）

外文翻译

题目

某大学科技楼结构设计及基坑支护

学院

建工学院

专　业

土木工程

班　　级

学　号

学生姓名

指导教师

教务处制

外文资料来源及题目（原文附后）。

1.资料来源：

指导老师给题

2.题目：

DesignChartsforPilesSupportingEmbankmentsonSoftClay

3.作者：

H.G.Poulos,F.ASCE

译成中文后题目（译文附后）

软土地基上桩承式路堤的设计图表

指导教师审阅意见：

签名：

年月日

DesignChartsforPilesSupportingEmbankmentsonSoftClay

H.G.Poulos,F.ASCE

Abstract:

Thispaperdescribesthedevelopmentandapplicationofdesignchartsforpiledembankmentdesigns.Itoutlinesthecomputationalapproachadopted,thegeotechnicalprofilesused,andtheapplicationofthedesignprocedureusingthecharts.ThesoilprofileusedforthechartsisrepresentativeofaMalaysiansoftclayprofile,involvingamoreorlessnormallyconsolidatedsoil,withastrengthandstiffnessthatvarieslinearlywithdepth.SuchaprofileistypicalofthegroundconditionsinavarietyofcountriesintheSoutheastAsianregion.Thedesignchartsaddresstheissuesofpilecapacity,settlementduetoembankmentload,settlementduetoatemporarypilingconstructionplatform,andlateralresponseofpilesneartheedgeoftheembankment.Thechartsconsidervariationsingroundconditions,embankmentheight,pilelength,andpilespacing.Anillustrativeexampleisgiventodemonstratetheuseofthecharts.

CEDatabasesubjectheadings:

Embankments;Foundationdesign;Lateraldisplacement;Pilefoundations;Settlement;Soilsettlement;Clays;Softsoils.

Introduction

Piledembankmentsprovideapossiblesolutionfortheconstructionofroadsandtransportcorridorsoversoftsoils.Theyhavetheadvantageofbeingrelativelyrapidtoconstructanddonotrequiretheextendedtimeperiodsthatmanyconventionalformsofgroundimprovementdemand（e.g.,preloading）.Piledembankmentshavebeenusedincreasinglyinanumberofregions,includingEurope,SoutheastAsia,andAustralasia.Avarietyofmethodsofdesignhavedeveloped,rangingfromrelativelysimplisticapproaches（forexample,BritishStandardsInstitution1995）torelativelysophisticatedmethodsinvolvingadvancednumericalanalysis（e.g.,RussellandPierpoint1997;Kemptonetal.1998;Hsi2001;HanandGabr2002;Wong2002）.Themajorityofthesimplermethodsaddressonlythestabilityorultimatelimitstate,orelsefocusontheissueofloadsharingandarchingbetweenthepilesandtheground（e.g.,TingandToh1983;HewlettandRandolph1988;Lowetal.1994）.

Thesimplerdesignmethodscurrentlyavailablegivelittleornoconsiderationtosettlementsanddeformations.Inmanycases,suchdeformationsmayhaveaprofoundinfluenceonthelongtermperformanceoftheembankment,anddesigncriteriafrequentlyspecifyupperlimitstothevaluesofsettlementanddifferentialsettlementthatcanbetolerated.Whileadvancednumericalanalysesmaybeappropriateandnecessaryfordetaileddesign,theyaregenerallynotsuitedtoarapidassessmentofthefeasibilityofpiledembankmentconstructionforaparticularsite.Tofacilitatepreliminaryassessmentanddesignofpiledembankments,aseriesofdesignchartshasbeendeveloped.Thechartsconsidervariationsingroundconditions,embankmentheights,andpiletypes.Forsimplicity,aperfectlyflexibleembankmenthasbeenassumed.Considerationisalsogiventotheeffectsofsoilmovementsarisingfromtheconstructionofatemporarypilingplatformfill（typically1to1.5mthick）.

ThesoilprofileusedforthechartsisrepresentativeofaMalaysiansoftclayprofile,involvingamoreorlessnormallyconsolidatedsoil,withastrengthandstiffnessthatvarieslinearlywithdepth.SuchaprofileistypicalofthegroundconditionsinavarietyofcountriesintheSoutheastAsianregion.

Thispaperdescribesthedevelopmentandapplicationofthedesignchartsforpiledembankmentdesigns.Itoutlinesthecomputationalapproachadopted,thegeotechnicalprofilesused,andtheapplicationofthedesignprocedureusingthecharts.Illustrativeexamplesaregiventodemonstratetheuseofthecharts.

GeotechnicalModel

AconsiderableamountofinformationonthegeotechnicalcharacteristicsofsoftmarineclaydepositsinMalaysiaisavailable（e.g.,Ramlietal.1994;RamliandIsmael,personalcommunication,1992;SagaeandGoh1997;Tanetal.2004）.Thereisanindicationthat,belowasurfacedesiccatedcrust2–3mthick,theclaysaremoreorlessnormallyconsolidatedandhaveanundrainedshearstrengththatincreaseslinearlywithdepth.Onthebasisoftheavailabledata,therelationshipchosenforthepresentstudyisrepresentedbytherelationship

su=10+1.5zkPa

（1）

wherez=depthbelowthesoilsurface（m）.

ThisrelationshipisperhapsmoreconservativethanthatsuggestedbyRamlietal.（1994）andistowardsthelowerendoftherangeofvaluesgivenbyTanetal.（2004）,butappearstobeareasonable（albeitconservative）fittothedata.

Fortheestimationofsettlementsduetosurfaceloadings,datafromtheavailablereferenceswasexamined,andvaluesadoptedforthecompressionratio[Cc/（1+e0）]intheupper15mwere0.30forthenormallyconsolidatedstateand0.05fortheoverconsolidatedstate.Below15m,thecompressionratiowastakentobe0.15forthenormallyconsolidatedstateand0.025fortheoverconsolidatedstate.Itisunderstoodthatthelowercompressionratiobelow15mmaybeaconsequenceofthissoilhavingalowerwatercontent,plasticityindex,andliquidityindexthanthesoilaboveit.Theupper5mwasassumedtobeoverconsolidated,withtheremainderofthesoilprofilebeingnormallyconsolidated.

Fortheestimationofpilesettlements,itwasassumedthattheembankmentpileswouldbedriven,andaccountwastakenoftheeffectsofpileinstallationinstiffeningthesoilaroundthedrivenpiles.BasedoncorrelationsdevelopedbyPoulos（1972D）forsoftclays,adrainedYoung’smodulusofthesoilaroundthepileof300suwasadoptedforthedesigncharts.Considerationisgivenhereonlytothelong-termsettlementsoftheembankment,whichincludebothundrainedandconsolidationcomponents,butexcludinganylong-termcreepsettlements.

Forestimationofpilecapacity,theultimateskinfrictionwasrelatedtotheundrainedshearstrengthviatheadhesionfactorα,whichisitselfafunctionofsu（Tomlinson1986）.Thevalueofαwastypicallywithintherange0.9–1.0.Theultimatebaseresistancewastakenas9sub,wheresub=undrainedshearstrengthinthevicinityofthepiletip.

Forthepurposesofthedesigncharts,thebasicvalueofthetotalthicknessofthesoftclaylayerwastakentobe40m,buttheeffectsofshallowerlayerdepthswerealsoinvestigatedandexpressedintermsofcorrectionfactorstotheresultsforthe40-mlayerdepth.Underlyingthesoftclayisalayerofstiffclay,whosepropertieswereassessedfromdatapresentedbyRamlietal.（1994）.Itisrecognizedthatthechosensoilprofileisratherspecificandthattheinfluenceofsuchimportantfactorsasstresshistory,stratigraphy,andsoilpropertiesarenotincorporatedintothisstudy.Nevertheless,itisfeltthatthechartsmayprovideareasonableindicationofthedesignrequirementsforpilessupportingembankmentsonrelativelythickdepositsofclaythatareessentiallynormallyconsolidated.

Fig.1summarizesthegeotechnicalmodeladoptedforthedevelopmentofthedesigncharts.

Fig.1.Assumedgeotechnicalprofile

DevelopmentofDesignCharts

Thedesignofpilesforpiledembankmentsrequiresconsiderationofatleastfourissues:

•Geotechnicalcapacityofthepiles;

•Settlementofthepiles;

•Lateralresponseofthepiles;and

•Structuralcapacityofthepiles.

Forthepurposesofdevelopingdesigncharts,attentionhereisfocusedonthefirsttwoissues,butsomeconsiderationisalsogiventotheothertwo.Ifthepileheadsareproperlyattachedtoaslabormattress,thenlateralpiledeflectionsshouldnotbeaconcernunlessgroundmovementsaregeneratedbysomeotheractivityadjacenttothepiles,e.g.,fillingorexcavation.Sucheffectsareexaminedinthispaper.Theaxialforcesforstructuraldesignofthepilesshouldincludeboththosearisingfromtheappliedloadingandthedowndragforcesdevelopedbygroundmovementsduetotheplacementoffillforapilingplatform.Considerationisalsogiventothesedowndragforceshere.

AnalysisProcedure

Themainanalyseswerecarriedouttoobtainthreeaspectsofthebehaviorofembankmentpiles:

1.Theaxialload-settlementbehavior,includingtheultimateaxialloadcapacityandthesinglepileheadstiffness;

2.Theeffectofgroupinteractiononpileheadstiffness;and

3.Theeffectonthepilesofverticalgroundmovementsinducedbytheconstructionofthefillforthepilingplatform（thepossibleeffectsoflateralgroundmovementswerenotconsidered）.

Fortheseanalyses,twocomputerprogramswereused:

PIES（forItems1and3above）andDEFPIG（forItem2）.BothprogramsweredevelopedattheUniversityofSydney,Australia.

PIEScomputestheaxialmovementandloaddistributionwithinapilesubjectedtoaxialloadand/orexternallyimposedverticalsoilmovements.Theprogramusesasimplifiedboundaryelementformulation,andthesoilcanberepresentedeitherbyanelasticcontinuumoraseriesofsprings.Ineachcase,nonlinearresponseoftheinterfacecanbeincorporatedbyassuminganelastic-plasticorhyperbolicrelationshipbetweensoilstiffnessandstresslevel,andbyallowingfortheeffectsofpile-soilslipandbasebearingfailurebyspecifyinglimitingvaluesofshaftresistanceandend-bearingresistance.

DEFPIGisaprogramforcalculatingthedeformationsandloaddistributionwithinagroupofpilessubjectedtovertical,horizontal,andmomentloading.Theprogramconsiders