土木工程工程管理前沿文献.docx

土木工程工程管理前沿文献.docx

《土木工程工程管理前沿文献.docx》由会员分享，可在线阅读，更多相关《土木工程工程管理前沿文献.docx（21页珍藏版）》请在冰豆网上搜索。

土木工程工程管理前沿文献

Contents

1Introduction

1.1EngineeringStatusatHomeandAbroad

Largesteelstructureisanimportantmeasurementcriterionofcountrytechnologicallevelincivilengineering.Itshighstrength,lightweigh,goodseismicperformance,shortconstructionperiod,highindustrializeddegreemakeitabetterbuildingmaterialthanconcrete.What’smore,spacesteelstructurebecauseofitsuniqueshapeandflexiblestructure,arewidelyusedinstadium,operahouse,gymnasium,exhibitioncenter,andairportterminals,etc.

Withthe2008BeijingOlympicGamesandJinannationalgamesand2009Shanghaiworldexpoheldinsuccession,Chinasteppedintoanewperiodofbuildingmegasteelstructure.Alargenumberofnovelstructure,largesteelstructurecanbesawinmanycities,likeNationalStadium（bird’snest）,NationalAquaticsCenter（ThewaterCube）,CCTVheadquartersbuilding,GuangzhouTelevisionTower,ShenzhenCitizensCenter,newterminalbuildingofthecapitalairport,everycountries’buildinginShanghaiWorldExpo,GuangzhouInternationalConferenceExhibitionCenter[1].

Largescale,widerange,longperiodandbuildingdifficultyisthecharacteristicsoftheseengineeringinconstructionstage.Structurelifecyclecanbedividedintothreestages[2]:

constructionphase,servicephaseandagingphase.

AsFigure1.2shows,theaverageriskrateinconstructionstageandagingstageismuchhigherthanthatinservicestage.Accordingtolargenumbersofengineeringaccidentinvestigation,about60%~90%engineeringaccidentswerehappeninconstructionstage,nomatterinthedevelopedwesterncountriesordevelopingcountries[3].Andthemainreasonofaccidentsisthelackofreasonableconstructionsafetycalculationanalysisandmanipulationerror.

Figure1.2LifeCircleofStructure

Owingtothecomplexityofspacesteelstructure,itsmechanicalperformanceiscomplexwhenitwassubjectedtoloading.What’smore,thestructureiseasytobedamagedbecausetheeffectonthestructureoftheexternalenvironmentloadchangeisbig.Therefore,theoverallstructuresafetystateevaluationisincreasinglyimportant.

Withtherapiddevelopmentofthespacestructure,projectaccidentshappeneveryyearintheprocessofconstructionandoperationshouldbepaidmuchattention[4~6].

1）2001,thespacetrussstructureofanofficebuildinginInnerMongoliacollapseintheseconddayofconstruction.

2）2004,onefactoryofShandongprovincecollapseduringerectionsagewhichkill5personsandseverelyinjured2persons.

3）2004,the3rdterminalbuildingofDubaiinternationalairportsuddenlyfelldowninerectionstage.

4）2007,oneofthesubwaystationinBeijingcollapseand3peopledieforit.

5）2010,thebridgeofKunmingnewairportprojectfelldown,whichkill7peopledieandinjured34people.

Thehighfrequencyofconstructionaccidentnotonlyimpactthesafetyofcitizen’slifeandproperty,butalsoinfluencethenationalconstructionplan.Hence,itseverelyimportancethekeeptheconstructionsafetyandlowertherateofprojectaccident.

1.2NecessityofConstructionSafetyCalculation

Thestressstatesofstructureduringconstructionandserviceperiodarequitedifferent.Incompletebuildingdesignphase,thestructureisintegratedandallthecomponentsustainloadingasasystem.However,duringconstructionstage,thestructureisincomplete,eachpartwasbuiltgraduallyastimegoingon.Inthisstage,everymemberofthebuildingsupportloadingasanindividual,whichmeansthatsomecomponentsweresubjectedtohigherloadingthandesignanditisverydangerous.What’smore,thestressconditionchangecontinuallywhenthestructureisbuilt.Especiallyforthespecialandcomplexsteelstructuresystem,likecantileverstructureorlargespanstructure,temporarysupportisneededduringconstructionstageandtheywillberemovedbeforecompletion.Inthiscase,thestressstatesarequitedifferentthanitincompletestate.Forexample,somemembersofstructureweresubjectedtotensionforceindesigncondition.However,duringconstructionstage,theymaybesubjectedtocompressionforce.Asweknow,thesteelbarisveryeasilybeunstablewhensubjecttocompressionforcewhichmaybenotinconsiderationduringcompletestructuredesign.Withoutconstructionsafetyanalysisandstructurehealthmonitoringduringconstructionstage,therateofaccidentwillshapelyincrease.

Therefore,constructionsimulationanalysisandstructurehealthmonitoringisverynecessarytokeepthestructuresafeduringconstructionstage.Beforeconstruction,itisveryimportanttocheckifthestructureissafebaseontheconstructionplan,ifitisdangerous,changetheconstructionprogramuntilthecheckresultconfirmthatthestructurewillbesafeandstableduringerectionstage[7].

Figure1.3Structuremechanicalconditioninconstructionperiod

Forconstructionstage,therearenoonlytheproblemofsafetybutalsotheproblemofthedesignshapeofbuilding.Moderncomplexsteelstructure,duetotheirlargesize,uniqueshapeappearance,complexnodesystem,iseasilyinfluencedbyconstructionfactorwhichmakethelocationofsteelmemberfardifferentwiththedesignplace.Hence,itisveryimportanttocalculatethedisplacementofeachmemberduringconstructionandmaketheadjustmentplan.Inaddition,duringconstructionstage,checkthelocationofsignificantparttomakesurethatthestructureperformasdesignbySHMsystem.

1.3Summary

Thespacesteelstructureconstructionisacomplexanddifficultprocedureinwhichtheaccidentrateisveryhigh.Hence,itisverynecessaryandurgenttodotheconstructionsimulationanalysisandstructurehealthmonitoring.

2ConstructionSimulationAnalysisBaseonMulti-ScaleModel

2.1ConstructionSimulationAnalysis

2.1.1BasicConceptofConstructionSimulationAnalysis

Constructionsimulationanalysisistheanalysismethodthattrytosimulationthewholeconstructionstageconditionbyfiniteelementsoftware.Numericalanalysisproblemduringconstructionstagebelongtotimevaryingmechanicalanalysisproblem.Whenloadingvaryastimegoingon,thestructurewillchangeself-shapetomaintaintheinternalforcebalance,whichiscalledtimevaryingstructure[8].

Inthelate19century,Meshcherkiifirstraisedtimevaryingrigidbodies’mechanicsintheessayaboutmeteoritesoil.In2000,GuangyuanWangdividedtimevaryingstructuremechanicsinthethreeregionanddefinedconstructionmechanicsintothesecondpart（timevaryinginslowspeedstructuremechanics）,maketheresearchdirectionandrangeofconstructionmechanicsclear[9].In2001,throughdescribingtheconstructionmechanicsanalysisanditsstudiesdirectionofthebaseoftimevaryingmechanics,YuanzhiCaoputforwardthemaintenbasicsubjectswhichformthebasicframeworkofcivilengineeringconstructionmechanics[10].Thecharacteroftimevaryingduringconstructionperiodisthatthestructureisbuiltfrombasiccomponenttoseveralpart,thenbecomeacompletestructure.Obviously,itisadynamicvariationprocess.Inthisprocess,thestiffness,elasticitymodulus,boundarycondition,loadingconditionarealwayschanging[11].

Forconstructionsimulationanalysis,alltheseconditionsarehopedtobesimulatedthenthepracticalengineeringcanbepredictedandtheconstructionprogramcanbechecked.

2.1.2BasicMethodofConstructionSimulationAnalysis

Nowadays,theconstructionmechanicsmethodmainlyincludetimevaryingelementmethod,topologychangingmethodandfiniteelementmethod[12].Finiteelementmethod,asamethodwhichcanbeeasilyunderstoodandcanbeprogramming,hasbeenwidelyusedincurrentconstructionsafetyanalysis.InFEM,therearethreeeffectivemethodincludingStatevariablessuperpositionmethod,birthanddeathelementmethodandstepbystepmodelingmethod[13].

2.1.2.1StateVariablesSuperpositionMethod

Statevariablerefertotheinternalforceanddisplacementofstructure.Theprocedureisthismethodisshowedasbelow:

[14]

a）DividedthewholeconstructionperiodintoNstagesbasetheerectionsequence.

b）BuildNcalculationmodelscorrespondingtoNconstructionstages.

c）Applydifferentloadingtoeachmodelandcalculatetheresponseofthestructure.

d）Superposetheresultofeachstructureinthesamepositiontogetthestructurefinalresponseafterconstruction.

Figure2.1Statevariablesuperpositionmethod

Thismethodcanbeeasilyunderstoodinconceptandhassimplecalculationprocess.Inaddition,thepropertyofapplyingloadingstepbystepcanbeconsidered,thatisthenextstagestructurewillnotsubjecttheloadinginpreviousstage.However,thismethodbaseonthelinearsuperpositionprinciple.Itsupposethatthewholeanalysisprocessislinearandtheresponseofstructureinlatterconstructionstagewillnotbeinfluencedbythatintheformerstage.What’smore,thismethodcannotconsidertheinfluenceofgeometricandmaterialnonlinearity.Hence,thismethodisonlysuitableforthesimple,symmetricandregularstructure.

2.1.2.2BirthandDeathElementMethod

Through“killing”or“activating”selectedelements,birthanddeathtechniquecansimulatethecomponenterectionanddismantlementduringconstructionperiod.Theelementbirthanddeathtechniqueismainlyusedintheanalysisofbuildingconstruction,minedigging,steelweldingandetc.Allofthemhavethepropertythatithavetoaddordeleteelementinanalysis.Whendeathtechniquewasadopted,itdoesnotmeanstodirectremovetheelementinthemodelbuttomultiplyaverysmallfactortothedeathelementstiffnessmatrix,usuallythefactorwassettobe

inANSY