Page 76 - 2024年第55卷第8期
P. 76

Studyondetectionofconcretesurfacecrackdepthusingsurfacewave
                                                 methodatameso - scale
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                                     1
                          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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