简介：Sincelocalscouratbridgepiersinriversandestuariesisamajorcauseofbridgefailure,estimationofthemaximumlocalscourdepthisofgreatimportancetohydraulicandcoastalengineers.Althoughnumerousstudiesthatfocusonscour-depthpredictionhavebeendoneandpublished,understandingoftheflowandturbulencecharacteristicsofthehorseshoevortexthatdrivesthescourmechanisminadevelopingscourholestillisimmature.Thisstudyaimstoquantifythedetailedturbulentflowfieldinadevelopingclear-waterscourholeatacircularpierusingParticleImageVelocimetry(PIV).Thedistributionsofvelocityfields,turbulenceintensities,andReynoldsshearstressesofthehorseshoevortexthatforminfrontofthepieratdifferentscourstages(t=0,0.5,1,12,24,and48h)arepresentedinthispaper.Duringscourdevelopment,thehorseshoevortexsystemwasfoundtoevolvefromoneinitiallysmallvortextothreevortices.Thestrengthandsizeofthemainvortexarefoundtoincreasewithincreasingscourdepth.TheregionsofboththemaximumturbulenceintensityandReynoldsshearstressarefoundtoformatalocationupstreamofthemainvortex,wherethelargeturbulenteddieshavethehighestpossibilityofoccurrence.Resultsfromthisstudynotonlyprovidenewinsightintothecomplexflow-sedimentinteractionatbridgepiers,butalsoprovidevaluableexperimentaldatabasesforadvancednumericalsimulations.