建筑大学外文翻译毕业设计用手翻 已过.docx

建筑大学外文翻译毕业设计用手翻 已过.docx

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建筑大学外文翻译毕业设计用手翻已过

外文文献：

GRAPHICAL-BASEDMULTISTAGESCHEDULINGMETHODFORRCBUILDINGS

Y.C.HUANG

DepartmentofConstructionManagement,HwaHsiaInstituteofTechnologyandCommerce,111HwaHsinStreet,ChungHoCity,TaipeiHsien,Taiwan,RepublicofChina

Received13February2004;accepted4March2005

InTaiwan,contractorsarebecomingspecializedincertaintypesofconstructioninanincreasinglycompetitiveenvironmentandthisspecializationrequiressomeschedulingmodelstoprovidebetterschedulingresultsforeachtypeofconstruction.Anewpracticalmethod,Graphical-BasedMultistageSchedulingMethod（GMSM）,forschedulingRCbuildingsuperstructuresispresentedherein.FromtheanalysisofcharacteristicsandconstructioncustomofRCbuildings,fourconstraints,（a）down–upconstruction,（b）buildinginspection,（c）reuseofbeamforms,and（d）reuseofslabforms,canbeestablished.TheGMSMisdevelopedutilizingagraphical-basedmethodandtheconceptofresourcereuse,andthegeneralformoftheGMSMtobefacilelyimplementedinanyworksheetsoftwareisderivedaswell.TheresultsofthisstudyprovidesomequantitativeinformationasausefulguideforschedulingRCbuildingsuperstructures.

Keywords:

Multistagescheduling,repetitiveproject,RCbuilding,GMSM

Introduction

InTaiwan,contractorsarebecomingspecializedincertaintypesofconstructioninanincreasinglycompetitiveenvironmentandthisspecializationrequiressomeschedulingmodelstoprovideabetterschedulingforeachtypeofconstruction.Themajorityofhigh-risebuildingslocatedinurbanareasinTaiwanareRCstructures.Itisdeemedcrucialforhigh-risebuildingsthataschedulingmodelforthistypeofconstructioncannotonlyincreaseprofitsbutalsoreducetheimpactonurbantraffic.

Ofthehigh-risebuildingsconstructedtodate,thenetworkplanningtechniquehasbeencommonlyadoptedinscheduling.TheCriticalPathMethod（CPM）isthemostpopularone;forinstance,prevalentschedulingsoftwaresuchasMSProject,PrimaveraProjectPlanner,etc.,weredevelopedbasedonCPM.However,assumingthatallactivitiesareindependent,theCPMdoesnottakeintoconsiderationtheresourcereusewherethereisrepetitionofidenticalactivitiesoneveryfloor.

O’Brien（1975）proposedthathigh-risebuildingbedividedintotwocategories:

（1）non-repetitiveworks,suchasearthworks,foundations,andnon-typicalfloorplans;and

（2）repetitiveworks,suchassuperstructureswithstandardfloordesigns.Intheformercategory,CPMisutilizedtoexecutescheduling.Forthelatter,aschedulingmodelsuitableforrepetitiveconstructionhastobedeveloped.Reda（1990）andCole（1991）alsodemonstratedthenecessityofschedulingforrepetitiveprojects.

Thisstudy,accordingtoO’Brien’ssuggestion,istodevelopagraphical-basedschedulingmethodapplicabletorepetitiveprojectsofRCbuildingsuperstructuressothatthemostpopularlypracticedconstructionmethodinTaiwan,sitecastconcretestructureswithwoodenforms,maybeinlinewithit.

Literaturereviews

Thetheoreticalschedulingapproachofrepetitiveprojectsisbasedontheprincipleof‘AssemblyLineBalance’,inwhichtherearetwopremises:

（1）workcontinuityforeachactivityfromoneunittothenext,and

（2）appropriatenessforthelower-boundlimitofconstructionintervalsbetweenadjacentactivitieswithinthesameunit.TheprincipalmethodsforrepetitiveschedulingaretheLineofBalance（LOB）methodandtheLinearSchedulingMethod（LSM）.ThedifferencebetweenthemisthatthedurationbetweenunitshavingidenticalactivitiesisassumedasaconstantforLOBmethod,andvariableforLSM（MoselhiandKhaled,1993）.

Inrecentdecades,fortheschedulingofrepetitiveprojects,anumberofmethodologieshavebeendeveloped,suchaslinearprogramming（HandaandBarcia,1986;Reda,1990（RPM）;RussellandCaselton,1998）,dynamicprogramming（Selinger,1980;RussellandCaselton,1988;EldinandSenouci,1994;SenoucandEldin,1996;El-RayesandMoselhi,2001）,simulation（Halpin,1977（CYCLONE）;Ashley,1980;Kavanagh,1985（SIREN）;AbouRizkandHalpin,1990;Lutzetal.,1994;ChehayebandAbouRizk,1998;ShiandAbouRizk,1998）,neuralnetwork（AdeliandKarim,1997）,andgeneticalgorithms（HegazyandWassef,2001;LeuandHwang,2001）.

Thecommonassumptionoftheabove-mentionedstudiesistheworkcontinuityforeachactivityfromoneunittothenext,ortheworkcontinuityonpartialunits.WangandHuang（1998）presentedamultistagelinearscheduling（MLS）methodtotackletheproblemofadjacentactivitiesofthesameunitrestrictedbyanupperlimitoftheintervaltime.IthasbeenfoundfromtheMLSmethodthattheintervalbetweenthestarttimesforadjacentunitsatleastequalsthelongestdurationamongallactivitiesinaunit.

Moreover,someschedulingmethodsforhigh-risebuildingshavebeenpresented.O’Brien（1975）presentedtheVerticalProductionMethod（VPM）,adoptingtheconceptofanassemblylinewithapredeterminedprogressrateofeachactivity.Agraphicaltechniquewasincorporatedtoinspecteachactivitywithregardtowhethertheconstructionlogicisachievedornot.ThabetandBeliveau（1994）analyzedthestarttimeofeachactivitywithinaunit,andestablishedaHorizontalandVerticalLogicScheduling（HVLS）proceduretomanagebothhorizontalandverticalconstraintsinhigh-risebuilding.Thisschedulingprocedurecanbeimplementedbasedoncriticalfloors,determinedbyhorizontaland/orverticalconstraintsasspecifiedbytheusers.Inaddition,ThabetandBeliveau（1997）usedaknowledge-basedsystemtoadjusttheHVLSproceduresothatitwouldsatisfytheconstraintsoffieldspaceandusefulresources.

Nevertheless,asthesemodelssatisfytheassumptionofcontinuousworkofidenticalactivitieson（partial）floors,theyareapplicabletosteelstructuresorSRCstructures.ThepurposeofthispaperistopresentaschedulingmodelforRCmultistorybuildings.Theproposedmodel,agraphical-basedmethod,isbasedontheconceptofresourcereusewithplainmathematicalmeanstodeterminethestarttimeforeachfloorofRCbuildings.DetailsofassumptionsandformulationoftheGMSMarepresentedinwhatfollows.

Assumptionsandconstraints

Assumptions：

ThroughanalysisofthecharacteristicsandcustomofconstructingRCbuildingsuperstructures,underlyingassumptionsonwhichtobasetheGMSMwereinducedandaresummarizedasfollows:

（1）workcontinuityofeachactivityismaintainedwithineachfloor;

（2）startinganyactivityonanyfloorsmustwaitforthecompletionofthesameactivityonthepreviousfloors;

（3）durationforeachactivityondifferentfloorsshallbeconstant;and

（4）theconstructionmethodshallremainthesameforeachfloor.

SincebothformworkersandrebarworkersaretwomaincategoriesoflaborintheconstructionofRCbuildingsuperstructuresinTaiwan,maintainingworkcontinuitywithineachfloorcanreduceidletime.Therefore,thefirstassumptionisinaccordancewiththeconstructioncustomofRCbuildings.Thesecondassumptionsatisfiestheresourcereuse.SincetheconstructionmethodofRCbuildingsconsistsofsomewell-definedactivities,thedurationforidenticalactivitiesperformedbyskilledformandrebarworkersoneachfloorisalmostthesame.Forsimplification,thedurationforidenticalactivitiesisassumedtobeconstantinpractice.Thefourthassumptionismatchedwiththedefinitionofrepetitiveconstructionofasuperstructurebyaspecificconstructionmethod.

Workflowofafloor

Fromthefourthassumption,onemustensurewhatactivitiesintheworkflowoffloorsare,andusetheworkflowasabasisforderivingtheGMSM.TheconstructionmethodofRCbuildingsuperstructuresinTaiwanusessitecastconcretestructureswithwoodenforms.TheworkflowofafloorforRCbuildingsconsistsofnineactivities,whichareshowninFigure1（a）.Atthesametime,itisassumed,fortheworkflow,thatthedurationfornon-critical-pathactivitiesshouldnotexceedthatofcritical-pathactivities.Forthematterofsimplification,lettheworkflowconsistofsevenserialactivities,whichisshowninFigure1（b）.

TheworkflowofafloorforRCbuildingscanbesimplifiedintoaseven-stepconstructionsequence:

（1）layoutofstructuremembers;

（2）settingcolumnreinforcements;（3）erectingwallandcolumnforms,andsettingwallreinforcements;（4）erectingbeamformsandshores;（5）erectingslabforms,stairsformsandshores;（6）settingbeams,slabsandstairsreinforcements;and（7）pouringconcrete,asshowninFigure1（b）.InFigure1,thesymbolsWiandDiusedinthisstudyrepresenteachactivityonfloorsanditsduration,respectively.

Becauseboththeactivitiesoflayoutofstructuremembersandpouringconcrete（requiringmoreprofessionalskillandpumpcarsthough）takeshorterdurationsthandoothers,contractorsusuallysubcontractthesetwojobstoreducecosts.Therestoftheactivitiesareperformedbyformandrebarworkers.

Constraintforscheduling

FromtheworkflowasshowninFigure1fortheschedulingprocessofRCbuildingsuperstructures,itisrequiredtoconsidernotonlytheinputoftheresource（e.g.theleastlaborcombination）andconstructability（theleastworkspace）foreachactivityonatypicalfloor,butalsothreefactors:

（1）down–upconstruction,

（2）regulationsofbuildinginspections,and（3）formreuse,ofwhichallaffectRCbuildingconstruction.Furthermore,thesefactorscanbetransformedintorestrictiveformulasforestablishingaGMSM

Constraintfordown–upconstruction

Ingeneral,anRCbuildingsuperstructureisconstructedbyrepetitivelyusingthesameconstructionmetho