简介:ThereisariverflowinginfrontofBainamVillageinDeqengTownofDarzeCounty.Becauseschools,infirmaries,supplyandmarketingcooperativesandmostofthefarmlandareallontheothersideoftheriver,anyonewhowantedaccesshadtoundertakeaninconvenient12-kindetour.Mattersbecameevenworseintherainyseason,whenthewaterlevelrose.
简介:Thispapersummarizesthedesignequationsforlocalscourdeptharoundbridgeabutmentsasproposedbydifferentinvestigators,andalsothedifferentfactors,affectingthescourdepth.Methodsfortheestimationoflocalscourdepthbasedondimensionalanalysisarealsopresented.Thedesignmethodsbasedonempiricalrelationssuchasflowdepth,flowintensity,sedimentcharacteristics,abutmentsshapeandsize,alignment,andapproachchannelgeometryarealsodiscussed.Sinceclear-waterscouristhemaximumscourdepth,theequationforclear-waterscourisrecommendedforthecomputationoflocalscourdeptharoundbridgeabutmentsforuniformlyandnon-uniformlygradedsediments.
简介:Anintegratedcouplingelementconsideringwheel-railinterfaceforanalyzingthedynamicresponsesofvehicle-rail-bridgeinteractionsystemwithanon-uniformcontinuousbridgeispresented.Thegoverningequationsoftheinteractionsystemareestablishedfirst,andthesolutionprocedureandassemblymethodofthecouplingelementaredemonstrated.Finally,theaccuracy,efficiencyandfunctionoftheintegratedcouplingelementaretestedusingtwonumericalexamples.Theinfluencesofdifferentcombinationsofrailandbridgeelementlengthinthecouplingelementonthesolutionareinvestigated,andtheeffectsofdifferentrailirregularitiesonthedynamicresponsesarediscussed.
简介:Tosystematicallystudythevehicle–bridgecoupleddynamicresponseanditschangerulewithdifferentparameters,avehiclemodelwithsevendegreesoffreedomwasbuiltandthetotalpotentialenergyofvehiclespacevibrationsystemwasdeduced.Consideringthestimulationofroadroughness,thedynamicresponseequationofvehicle–bridgecoupledsystemwasestablishedinaccordancewiththeelasticsystemprincipleoftotalpotentialenergywithstationaryvalueandthe‘‘set-in-right-position''rule.Onthebasisoftheself-compiledFortranprogramandbridgeengineering,thedynamicresponseoflongspancontinuousgirderbridgeundervehicleloadwasstudied.Thisstudyalsoincludedthecalculationofvehicleimpactcoefficient,evaluationofvibrationcomfort,andanalysisofdynamicresponseparameters.Resultsshowtheimpactcoefficientchangeswithlanenumberandislargerthanthevaluecalculatedbythe‘‘generalcodefordesignofhighwaybridgesandculverts(China)''.TheDieckmannindexofbridgevibrationisalsorelatedtolanenumber,andthevibrationcomfortevaluationisgoodinnormalconditions.Therelevantconclusionsfromparametricanalyseshavepracticalsignificancetodynamicdesignanddailyoperationoflong-spancontinuousgirderbridgesinexpressways.Safetyandcomfortareexpectedtoimprovesignificantlywithfurthercontrolofthevibrationofvehicle–bridgesystem.