Page 75 - 2024年第55卷第1期
P. 75
Analysisoftheinfluenceofvegetationontheriverbankstabilityinthe
LowerJingjiangReachunderwaterlevelchange
QIUJiaqi,YUMinghui,LIQian
(StateKeyLaboratoryofWaterResourcesEngineeringandManagement,WuhanUniversity,Wuhan 430072,China)
Abstract:Toanalyzethetypicaltopclay - bottomsandbankslopeoftheLowerJingjiangReach(LJR),theveti
vergrass - tallfescuewasselectedastheprotectiontype,regardingtherootanchorageeffectandtranspirationofthe
vegetation.UsingGeoStudiotoimitatethestrengthandthermodynamicindicatorsofthebank ,studyingtheinflu
enceofthemagnitudeofwaterleveldecline ,rateofwaterleveldeclineandinitialwaterlevelonbankstabilityby
singlefactoranalysisapproach,andcomparingthedegreeofinfluenceofthethreefactorsbygreyrelationalanaly
sis.Theresultsshowthat :asthewaterleveldecline,thesafetyfactorofbankslopefirstdecreasesrapidlyand
thentendstostablevalues ;bankstabilityismostinfluencedbytherapidrateofwaterleveldecline,whentherate
ofwaterleveldeclineislessthan1m?d,thebaresoilsloperemainsinabasicstablestate;whenitisgreaterthan
3m?d,theslopebecomesinstability.Vegetationcanimprovethebankstability,comparingthevegetatedslopeto
thebareslope,itssafetyfactorcanbeincreasedby4.33% atmost;thecorrelationbetweenthesafetyfactorof
bankslopeandthethreefactorsdecreasesundervegetatedcondition,withadecreaseof3.73% atmost.There
sultsclarifiedtheeffectofthevegetationonthebankstabilityoftheLJRunderwaterlevelchangeandprovidearef
erenceforecologicalbankprotectionprojects.
Keywords:ecologicalrevetment;LowerJingjiangReach;bankstability;waterleveldecline
(责任编辑:耿庆斋)
(上接第 59页)
FailurelawofPCCPcausedbybrokenwires Ⅱ:Numericalsimulationstudy
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DOUTiesheng,DONGXiaonong,NIUWenlong,LIYanlong,NINGJinghua,LIKangping
(1.StateKeyLaboratoryofSimulationandRegulationofWaterCycleinRiverBasin,ChinaInstituteofWaterResourcesand
HydropowerResearch ,Beijing 100038,China;
2.StateKeyLaboratoryofEco - hydraulicsinNorthwestAridRegion,Xi’anUniversityofTechnology,Xi’an 710048,China;
3.PowerchinaShandongPipelineEngineeringCorporationLimited,Jinan 250117,China)
Abstract:Numericalsimulationofwirebreakageinprestressedconcretecylinderpipes(PCCP)currentlyeither
removestheentirecirclecontainingthebrokenwireorassumesafixedrangeineachbrokenwireregainingitsfull
tension ,withoutconsideringwhetherthisrangeduetomortardamagecanbeextended.Thispaperabstractlyana
lyzestheinteractionmechanismsbetweenthemortar ,steelwires,andcoreconcreteofPCCP,introducesthe
springelement ,cohesivecontactmodel,andconcreteplasticdamagemodel,proposesafull - processsimulation
methodforprestressingthecoreconcrete ,cuttingsteelwiresatarbitraryposition,andforminganextendable
rangeineachbrokenwireregainingitsfulltension,andclarifiesthekeyparametersforregulatingtheinitialsize,
extensiontiming,andextensionamplitudeofthisrange.Basedonprototypetests,numericalmodelswereestab
lishedforclusteredandscatteredwirebreakageunderconstantinternalpressure ,andtherationalityofthenew
simulationmethodwasverifiedfrom theperspectiveoftheentireprocessfrom internalpressureloadingtowire
breakagefailure.Andtheserevealthelawsoftheprestresslossandfailureofthecore ,makeitpossibletosimu
latevariousthree - dimensionalbreakpointdistributionsinpracticalengineering ,andprovideanewmeansfor
moreaccuratepredictionandevaluationofthestructuralperformanceofthewire - brokenPCCP.
Keywords:PCCP;clusteredwirebreakage;scatteredwirebreakage;numericalsimulationmethod;prestress
loss;failure
(责任编辑:韩 昆)
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