Page 76 - 2024年第55卷第8期
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Studyondetectionofconcretesurfacecrackdepthusingsurfacewave
methodatameso - scale
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SUNLinyuan,HUANGHao ,CHENKang ,ZHENLi ,CHENGaixin
(1.ChinaInstituteofWaterResourcesandHydropowerResearch,Beijing 100038,China;
2.ChinaInstituteofWaterResourcesandHydropowerResearchStateKeyLaboratoryofSimulationandRegulationof
WaterCycleinRiverBasin ,Beijing 100038,China;
3.KeyLaboratoryofEngineeringMaterialsofMinistryofWaterResources,Beijing 100038,China)
Abstract:DetectingthedepthofconcretesurfacecracksbasedontheR - wavecutofffrequencyisaneffectivenon -
destructivetestingmethod.Currently,thefrequencytransmissionratiomethodiscommonlyusedtoidentifythe
cutofffrequency;however,thismethodisgreatlyaffectedbytheconcrete’smeso - structure,leadingtosuboptimal
identificationresults.Toenhancetheaccuracyofcutofffrequencyidentification,thispaperproposesthemulti -
channelsignalphaseshiftdispersionanalysismethod.Finiteelementsimulationswereconductedtodetectthedepth
ofsurfacecracksinuniformmediaandconcretemeso - modelsusingR - waves.Thedetectionmechanismsandiden
tificationeffectsofthefrequencytransmissionratiomethodandthemulti - channelsignalphaseshiftdispersionanal
ysismethodwerecomparedandstudied.Standardsforidentifyingthecutofffrequencywereprovided ,andthe
effectsofaggregatesize ,porosity,anddetectionfrequencyonthemulti - channelsignalphaseshiftdispersionanal
ysismethodwereanalyzed.Theresearchresultsindicatethatthemulti - channelsignalphaseshiftdispersionanaly
sismethodhasbetteridentificationeffectsandisnotaffectedbythemeso - structureandthecrackthicknessratio.
Changesinaggregatesize ,content,andelasticmodulusbasicallydonotaffectthemethod’seffectiveidentification
ofthecutofffrequency.WhentheR - wavewavelengthislessthanthethicknessofthecomponentandtheporosity
doesnotexceed4%,themethodstillexhibitsgoodidentificationeffects.Thisstudycanprovideatheoreticalbasis
forthequantitativedetectionofconcretesurfacecrackdepthinpracticalengineering.
Keywords:concretesurfacecrackdepth;meso - structure;cutofffrequency;frequencytransmissionratiomethod;
dispersionanalysisofphaseshiftmethod
(责任编辑:韩 昆)
(上接第 941页)
Analysisandexplorationonthepotentialityofwaterfront
environmentqualityimprovementinBeijing
YANGShuyuan,ZHANGXiaoxin,WEIBaoyi,ZHAOJie,HANShanshan
(BeijingMunicipalInstituteofCityPlanningandDesign,Beijing 100045,China)
Abstract:Thecomprehensivemanagementofurbanwaterfrontspaceisbecomingmoreandmorecontinuous,
systematicandcomplex.Therearestillsomedeviationsinthekeypointsandconstructiontimingoftheimprove
mentofurbanwaterfrontspacemanagement.Inthispaper ,theimportantrivercoursesintheCentralCityofBei
jingistakenasanexample.Firstly,thecoreevaluationindexesofwaterfrontenvironmentalqualitywereidenti
fied,andthespatio - temporalbigdatacombinedwithGISspatialanalysismethodareusedtoquantitativelyevalu
atethetotalfactorsofthecurrentsituationofwaterfrontspace.Inthenewera ,themainfocusoftheimprovement
ofriverandwaterfrontspacequalityistheimprovementoftrafficaccessibility ,theperfectionofhumanandsup
portingservicefacilities ,andtheconstructionofopengreenspace,etc.Secondly,theinternaldrivingforceof
theenvironmentalqualityofurbanwaterfrontspacewasanalyzed,putingforwardamulti - dimensional,multi -
level,all - factorindexsystemofurbanwaterfrontspacepotentialanalysis.Thecouplingandinteractivemodelof
supplyanddemandwasconstructed ,andtheanalysismethodofurbanwaterfrontspatialpotentialwasestablished.
Finally ,basedontheanalysisandevaluationresultsofwaterfrontspatialpotentialandlandresourcesonbothsides
oftheriver ,a“three - level - two - class” urbangovernanceplanwasformulated,highlightingtheleadingroleof
planning ,focusingonthematchingofwaterfrontspaceimprovementandtransformationwiththeoveralldevelop
ment ,constructionanddemandsofurbandistricts,andformingabenigninteractivemechanism.
Keywords:waterfrontspace;supply - demandcouplinginteractionmodel;evaluationindexsystem;environmental
qualityimprovement;planningleading
(责任编辑:李 娜)
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