Page 35 - 2024年第55卷第2期
P. 35

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)

                                                                                                —  1 5 7 —
   30   31   32   33   34   35   36   37   38   39   40