外文翻译第页英文RotationalMomentAnalysisandPostureRectificationStrategyofShieldMachineAbstract.Therollingphenomenonoftheshieldbodyoccursfrequentlyintheprocessofpracticeconstruction,whichcouldleadtothederivationoftheshieldmachineandincreasethedifficultiesoftheexcavationcontrol.Itismainlycausedbytherotationofthecutterhead.Basedonthispracticalproblem,weinvestigatetheforcesaroundtheshieldbodyandthecutterhead.Meanwhile,thepositiveandnegativerotarycontrollingtechniquesaredevelopedtoregulatethedeviatedrollingangle.Thesestudieswouldprovidetheoreticalbasistothefurtherresearchaboutthewholeposturesrectificationoftheshieldmachine.Keywords:Shieldmachine,Rotationmomentanalysis,Rectificationstrategy.1Introduction1.1ShieldTunnelingMethodShieldmachineisanimportanttechniqueequipmentinbasicconstructionandresourcedevelopment,whichiswidelyappliedintunnel,railroad,highway,mineralmountainetcundergroundconstruction.Theshieldtunnelingmethodisamethodtoconstructtunnelwithshieldmachine.Duringshieldexcavation,thejackattheshieldtailpushthetunnelsegmentwhichhadbeenassembledwhereareactionforceoccurredtomaketheshieldgoingforward,atthesametimetheexcavationplanemustkeepstabile.Comparingwithcutandcovermethod,shieldtunnelingmethodhavesomemeritsasfollows:1,Lessoccupiedgroundsurface,lesslandexpropriationcost.2,Theinfluenceofweatherconditionissmall,sotherewillbelongereffectiveconstructiontimecomparatively.3,Softsoil,sandeggsoil,softrockandtherockstrataareallapplicable.4,Theconstructionspeedisquick.5,Theinfluencetotheenvironmentissmall.Accordingtotheabovemerits,theshieldtunnelingmethodgetextensiveapplication.1.2RotationPostureRectificationPositionandpostureofshieldmachineisimportanttoprecisionoftunnelconstructionduringexcavation.Buttheremusthavedeviationfromactualpositionandposturetodesiredpositionandposture.Sotherectificationofthedeviationisnecessary.Inthispaper,wedonotdiscusspositionrectification.Inposturerectification,onlyrotationrectificationisconsidered.Postureofshieldmachineisdescribed