Metrotrain-inducedvibrationsonhistoricbuildingsinC

782Maetal./JZhejiangUniv-SciA(ApplPhys&Eng)201112(10):782-793JournalofZhejiangUniversity-SCIENCEA(AppliedPhysics&Engineering)ISSN1673-565X(Print);ISSN1862-1775(Online):[e-mail]-inducedvibrationsonhistoricbuildingsinChengdu,China*MengMA†1,2,ValériMARKINE2,Wei-ningLIU1,YangYUAN1,FengZHANG1(1SchoolofCivilEngineering,BeijingJiaotongUniversity,Beijing100044,China)(2SectionofRoadandRailwayEngineering,DepartmentofDesignandConstruction,DelftUniversityofTechnology,Delft2600GA,theNetherlands)†E-mail:[e-mail].3,2011;RevisionacceptedAug.18,2011;CrosscheckedSept.8,2011Abstract:Inthispaper,thevibrationinfluenceonamonumentcausedbyChengduSubwayLine2isanalyzed.Duetoitselaborateanduniquedesign,bothstructuralandarchitecturaldamagesshouldbeavoided.First,theallowablerootmeansquare(RMS)velocityatthefoundationofthemonumentisderivedandasitemeasurementisperformedtoobtainthebackgroundvibrationsinducedbyroadtraffic.Inaddition,atrain-trackcoupledmodeland3Dtunnel-soil-structurecoupledfiniteelementmodelsarebuilttopredictthedynamicresponseofthemonument.PredictionmodelsarecheckedbysitemeasurementinBeijingSubwayLine5.Differentkindsoffastenersandtrainspeedsarecomparedanddiscussedaswell.Resultsshowthat:(1)Atatrainspeedof72km/h,allthetrafficvibrationsexceedthelowlimitnomatterwhatkindoffastenerisused,whichismainlyduetothecontributionofroadtraffic.Slowingdowntrainspeedscancauseeffectivevibrationattenuation;(2)Vibrationsdropdramaticallywiththetrainspeedfrom65to58km/h.Whenthetrainspeedislowerthan58km/h,vibrationsarelowerthanallowablevalueevenifthecontributionofroadtrafficisconsidered.Keywords:Trafficvibrations,Historicbuildings,Vibrationprediction,Numericalsimulationdoi:10.1631/jzus.A1100088Documentcode:ACLCnumber:U231;TB533.21IntroductionWiththerapiddevelopmentoftheurbanrailtransitsystemandtheconstructionofbuildings,ground-bornevibrationsinducedbysubwaytrainsandtheirinfluenceonbuildingstructureshavebe-comemajorenvironmentalconcernsinurbanareas.Generally,itisextremelyrareforvibrationsfromtrainoperationstocauseanysortofbuildingdamage,evenminorcosmeticdamage(Heckletal.,1996).However,thereissometimesaconcernregardinglong-termvibrationeffectsonhistoricbuildingslo-catednearthesubwaylines.Trafficvibrationsare*ProjectsupportedbytheNationalNaturalScienceFoundationofChina(No.51008017),andtheFundamentalResearchFundsfortheCentralUniversities(Nos.2009JBM074and2009JBM075),China©ZhejiangUniversityandSpringer-VerlagBerlinHeidelberg2011usuallylow,butlasting,whichcouldleadtopotentialdamage,likebuildingmaterialfatigueandfounda-tionsettlementtohistoricbuildings.Forstructuresthathavesufferedfromweathering,desquamation,orhavecracks,evenlowvelocitiescouldgiverisetofatiguedamagewithfrequentoccurrences.InEurope,damagetosomehistoricbuildingscausedbyroadtraffichasbeenreportedbyBata(1971)andClementeandRinaldis(1998).Toprotectheritagebuildingsagainsttraffic-inducedvibrations,manystudieshavebeenperformedinGreatBritain,Italy,andSpain(Ellis,1987;Bazacoetal.,1995;Chiostrinietal.,1995;Sanòetal.,1998;CrispinoandD’Apuzzo,2001;PauandVestroni,2008).InChina,therehasbeendoubtthattherapiddevelop-mentofdesquamationandcracksoffrescoesandsculpturearerelatedtothetrafficvibrationsintheLongmenGrottoesandDunhuangGrottoes.SomeMaetal./JZhejiangUniv-SciA(ApplPhys&Eng)201112(10):782-793783studieshaveindicatedthat,bythevibrationofrail-wayandhighway,thedisasterstotheLongmenGrottoesfromvibrationinthelast30yearshasex-ceededthetotalexperiencedintheprior1000–1500years(Zhang,2002;Leietal.,2009).Tounderstandfurtherhowtoprotecthistoricbuildingsagainstsubwaytrain-inducedvibrations,theroutedesignandisolationmethodshavebeenstudiedforBeijingLines4,5,6,8,and9andtheStraightRailwayLineandXi’anLines2and6(Liuetal.,2007;Jiaetal.,2008;Maetal.,2009).Notethattherearetwokindsofbuildingdam-age:structuralandarchitectural.Theformerwilldestroysomestructureelementsandendangerthesafetyofthesebuildings,whilethelatterwilljustcausecosmeticdamageorcrackswhich,however,arealsonotallowedforthosewithsuperiorartisticvalueorhistoricvalue.Inthispaper,acasestudyontheeffectsofvibrationfromChengduSubwayLine2ispresented.Bothsitemeasurementsandnumericalsimulationsareperformedtoanalyzetheeffectofvibrationfromroadtrafficandsubwaytrains.structures,itisbelievedthataPPVlowerthan10mm/swillrarelycauseanysortofbuildingdam-age.Forhistoricbuildingsandmemorials,thecriteriaareusuallystricter,from3to10mm/sPPV,de-pendingonlocalcodes,whicharesummarizedbyMaetal.(2009).Numerousmeasurementsshowthattypicalgroundvibrationlevelsfromundergroundtunnelslieintherangeof0.05–1.00mm/s,lowerthanthevaluesinthecodesmentionedabove,buttheyremainsthepossibilityofdamagestohistoricbuildings.Thatis,thePPVsbetween3and10mm/sdonotgenerallyconsiderarchitecturaldamage,butratherstructuraldamage.2Problemoutline2.1DescriptionofhistoricbuildingsThehistoricmonumentislocatedinthePeo-ple’sPark,centerofChengduCity,China(Fig.1).ItwasbuilttorememberthemartyrsstrugglingfordefendingrailwaysovereigntyintheA