专业英语 不均匀沉降 混凝土路面 应力应变监测.ppt

StrainMonitoringofWideningCementConcretePavementSubjectedtoDifferentialSettlementofFoundation 地基不均匀沉降下的宽混凝土路面的应力应变监测 Catalog AbstractKeywordsBackgroundMainContentResultsandDiscussionReferences Abstract ThispaperdescribestheuseofasensorbasedonafiberBragggrating FBG whichiscapableofreducingstraintransfererrors tomeasurethestrainfeatureswithinthetopandbottomlayersofacementconcretepavementsubjecttodifferentdegreesoffoundationsettlement Basedonmeasureddata thecharacteristicsofthedistributionandthevariationinthestructurestrainwereanalyzedindetail 本文介绍了基于光纤光栅原理的一种传感器 这种传感器能够减少应变传递误差 并测量顶层和底层受不同程度的基础沉降影响的水泥混凝土路面的应变功能 基于实测数据 详细分析了该结构应变分布的特点及变化规律 Bycomparingthemeasuredresultswiththoseobtainedbymeansoffiniteelementanalysis theproposedFBGbasedsensorassemblywasfoundtobecapableofeffectivelymonitoringthestraindistributioninacementconcretepavement thusprovingthattheimprovedopticalfibergratingstrainsensorisaverypromisingsolutionforroadpavementstructuralhealthmonitoring 通过实测结果与有限元分析的方法比较 可以看出该光纤光栅传感器组件是能够有效地监测的应变分布在水泥混凝土路面 进一步也证明改进后的光纤光栅应变传感器对于路面结构健康监测方面的研究是一种很有前景的解决方案 KeywordsFBG Sensors StrainMonitoring CementConcretePavement DifferentialSettlementofFoundation Themainadvantagesofopticalfibersensorsoverconventionalmonitoringtechniquesincludetheirimmunitytoelectromagneticinterference theirsmallsize andlightweightconstruction whichcanovercomethelimitations Opticalfibertechnologyhasbeenwidelyusedforstructuremonitoringincivilengineering Manyroadwideningprojectsquicklysawtheappearanceofmanylongitudinalcracks soonafterthecompletionofconstruction Therefore researchintoroadwideningprojectshasverypracticalsignificance Background ThispapermainlydescribestheuseofanFBGsensortomonitorthestrainfeaturesofaconcretepavementstructureinfullsizemodeltesting Thepaperisdividedintotwoparts Inpart1 wepresentthephysicalbackgroundtoBragggratingsensorsandtheirapplicationtofull sizemodeltests Inpart2 theresultsofexperimentsarepresentedandcomparedwiththoseoffinite elementsmethod FEM simulations Background MainContent Bragggratingreflectinglightwavewithspecificwavelength Whenabroadbandlightsourceisinjectedintotheopticalfiber theFGBwillreflectapartofnarrowspectrumlightwithspecificwavelengthandthengenerateacertainreflectionspectrum Thecenterwavelengthofthereflectedlighthasaspecificrelationshipwiththeopticalfiberstrainandtemperature FBGsensorisalsoverysensitivetotemperaturechange sothetemperature compensationproblemmustbesolved Duringthetest byaddinganothertemperaturesensor thetemperature ofthesamefieldismeasured andthentheteststrainvalueswouldbemodified MainContent Themainapplicationdifficultyoriginatesintwoareas Firstoneistheaccurateinstallationandon siteprotectionofthefiberopticcabletransmissiongrating Toallowthefibergratingtoreflectthedeformation stress andotherphysicalvaluesofthestructure itisnecessarytoensuresynchronizationdeformationbetweenthefibergratingandtheobject Inaddition toaccuratelyobtainthestraininthepavementstructureanditsvariationwithtemperature fibergratingreadingsmustisolatestrainandtemperatureintheprocessoflong termmonitoring MainContent Theliftsystemofthemodeltestsimulationplatformconsistsofhydraulicjacks whichcansimulatethesettlingvaluesandthesedimentationrateofthefoundations Themultiplerigpanelsofthetestplatformareassembledintoa groundsurface withmanualcontrol whiletranslationalandrotationalmovementsareachievedusingtheactivitiespanelunderthecontroloftheliftingsystem whichcanbeapproximatedbysimulatingtheactualsurfacefoundationsettlement MainContent Toeffectivelyprotectasensorinhostileconstructionenvironmentsandthusattainreasonablemonitoringdata aprotectionsystembasedonatube packagewasdevelopedandimplemented MainContent Itcanbeseenthatthestraingraduallyincreaseswiththeincreasein Arelativelysteadystagewithsmallmagnitudeisobservedbefore reaches8cm When surpasses8cm however thestrainbeginstoincreasemorerapidly Atthispoint duetotheadditionalstresscausedbyconsiderabledifferentialsettlementoftheground structuralfailuredevelopsinthepavementandcrackingoccursonthesurface MainContent AsshowninFigure8 thestraindataforNodes1to12wereobserved soastoobtainthestraincurvesfortheconcretepavementsubjectedtodifferentialsettlementofthefoundation Figure9 ResultsandDiscussion AcomparisonbetweenthemeasuredandFEAresultsshowedthatbothresultsexhibitthesamevariationsandtrends whichshowthattheimprovedopticalfibergratingstrainsensorconstitutesaverypromisingsolutionforapplicationtoroadpavementstructuralhealthmonitoring aswellasothercivilstructures References 1 Y B Lin C L Pan Y H Kuo K C Chang andJ C Chern OnlinemonitoringofhighwaybridgeconstructionusingfiberBragggratingsensors SmartMaterialsandStructures vol 14 no 5 pp 1075 1082 2005 2 T Matsumoto P Kitiyodom H Matsui andY Katsuzaki Monitoringofloaddistributionofthepilesofabridgeduringandafterconstruction SoilsandFoundations vol 44 no 4 pp 109 117 2004 3 J M Lopez Higuera C J Misas A Q Incera andJ Echevarr aCuenca Fiberopticcivilstructuremonitoringsystem OpticalEngineering vol 44 no 4 2005 4 S C HerandC Y Tsai Strainmeasurementoffiberopticsensorsurfacebondingonhostmaterial TransactionsofNonferrousMetalsSocietyofChina vol 19 supplement1 pp s143 s149 2009 5 K Kesavan K Ravisankar S Parivallal P Sreeshylam andS Sridhar Experimentalstudiesonfiberopticsensorsembeddedinconcrete Measurement vol 43 no 2 pp 157 163 2010 6 A Klar I Dromy andR Linker Monitoringtunnelinginducedgrounddisplacementsusingdistributedfiber opticsensing TunnellingandUndergroundSpaceTechnology vol 40 pp 141 150 2014 7 X Weng H H Zhu J Chen D Liang B Shi andC C Zhang Experimentalinvestigationofpavementbehaviorafterembankmentwideningusingafiberopticsensornetwork StructuralHealthMonitoring vol 14 no 1 pp 46 56 2015 References 8 Z Zhou W Liu Y Huangetal OpticalfiberBragggratingsensorassemblyfor3Dstrainmonitoringanditscasestudyinhighwaypavement MechanicalSystemsandSignalProcessing vol 28 pp 36 49 2012 9 Y Chen L V Yue andZ Zhang Thecauseoflongitudinalpavementfissuresandpreventionsonhighwayroad wideningengineering EastChinaHighway vol 40 no 1 pp 38 41 2003 Chinese 10 W Xiaolin L Lintao andZ Liujun Modelexperimentalresearchonwettingdamagemechanismofwideningloessroadbed ChineseJournalofRockMechanicsandEngineering vol 29 no 5 pp 1075 1081 2010 Chinese 11 H JieandA Ken Useofgeogrid reinforcedandpilesupportedearthstructures inProceedingoftheInternationalDeepFoundationCongress pp 668 679 ASCE Orlando Fla USA February2002 12 H Qinlong L Jianming andT Boming Experimentalresearchonincoordinatedeformationbetweenexistingsubgradeandthewideningone JournalofHighwa