Page 35 - 2024年第55卷第2期
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Refinedfailureanalysisandfunctionalevaluationofcutoffwallsof
rockfilldamsondeepoverburden
1,2
1,2
1,2
1,2
ZOUDegao ,QUYongqian ,KONGXianjing ,LIUJingmao ,
3
RANCongyong,ZHANGDan 3
(1.StateKeyLaboratoryofCoastal&OffshoreEngineering,DalianUniversityofTechnology,Dalian 116024,China;
2.SchoolofHydraulicEngineering,DalianUniversityofTechnology,Dalian 116024,China;
3.PowerChinaChengduEngineeringCorporationLimited,Chengdu 610072,China)
Abstract:Theconcretecutoffwallisthekeyanti - seepagestructureforthefoundationofrockfilldamsontheover
burden.Duetothesignificantdifferenceinstiffnessandscalebetweenthecutoffwallandtheoverburden ,conven
tionalnumericalanalysismethodsstruggletoensureaccuracy.Moreover,currentstrength - basedsafetyevaluation
methodscannotadapttothefunctionalevaluationrequirementsofthecutoffwallasanimpermeablestructurerather
thanaload - bearingstructure.Inthispaper ,arefinedanalysismethodisproposedtodescribetheevaluationofan
ti - seepageperformancetargetsaftercompressiondamageandtensilecrackingandbreakagebycouplingthepropor
tionalboundaryelement - finiteelementcross - scalediscretization,theplasticdamagemodel,andthecohesion
modelseparately ,andtorealizetheevaluationoftheperformanceevolutionofthecutoffwalloftherockfilldamson
thedeepoverburden.Theresultsindicatethatthehanging - typecutoffwallsontheultra - deepoverburdenundergo
pressuredamageatthebottom onbothsidesduetohighcompressivestressesapproximatelyperpendiculartothe
bankslope.Thein - planebendingdeformation ,resemblingan“outstretchedbeam”,induceshightensilestresses
inthetopandbottomregionsnearthebanksofthecutoffwall,resultinginverticalcracksbetweenadjacentsec
tions.Theauxiliarycutoffwallsontheupstreamsideisaneffectivemeasureinreducingtheseepageflowafterdam
agetothecutoffwall.Theproposedmethodrevealsthedamageandcrackingpatternsofconcretecutoffwalls ,lo
catesweakareasofthecutoffwall ,evaluatestheeffectofdamage - inducedcrackingonanti - seepageperformance,
andquantifiestheeffectivenessofmeasures.Thismethodbridgesthegapfromthetraditionalload - bearingcapacity
evaluationtothefunctionalperformanceevaluationofcutoffwalls ,providingtheoreticalandtechnicalsupportfor
thesafetyevaluationanddesignoptimizationofcutoffwallsofrockfilldamsondeepoverburden.
Keywords:deepoverburden;cutoffwall;failureanalysis;anti - seepagefunction;functionalevaluation
(责任编辑:李福田)
(上接第 146页)
Waterhammerpneumaticpressuretankandhydraulictransientsimulation
YANGKailin
(StateKeyLaboratoryofSimulationandRegulationofWaterCycleinRiverBasin,
ChinaInstituteofWaterResourcesandHydropowerResearch,Beijing 100038,China)
Abstract:Airvalvesareofteninstalledonthesidewallofthewatersupplypipemanhole,andsomeofthegas
willremainintheupperpartofthemanholeafterintake,creatingthewaterhammerprotectioneffectoftheair
cushionpressuretank.Basedonthis ,adesignmethodforawaterhammerpneumaticpressuretankdeviceispro
posed ,whichutilizesthenegativepressurephenomenonofwaterhammergeneratedbythepoweroutageofthe
pumpstationaccidenttosupplementthepressuretankwithairthroughavacuumbreakingvalveorairvalve ,so
astopreventliquidvaporizationinthewaterpipelineandreducethemaximumpressureofwaterhammer.Then ,
anumericalsimulationmathematicalmodelwasestablishedforthehydraulictransientsofthewaterhammerpneu
maticpressuretanks.Finally ,takinganactualwaterdiversionprojectasanexample,thewaterhammerprotec
tioneffectsofsettingairvalves ,airvalveregulatingchambers,andvacuum breakingvalvepneumaticpressure
tanksrespectivelywerecalculatedandcompared.Theresultsshowthatthevacuum breakingvalvepneumatic
pressuretankshasthebestwaterhammerprotectioneffects.
Keywords:waterhammer;airvalve;vacuumbreakingvalve;pressuretank;airreplenishment;simulation
(责任编辑:李福田)
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