Mohammad Vaghefi

Culvertsarestructuresdesignedtofacilitatethetransferofwaterbeneathroadways,effectivelyconnectingtwo areas within a catchment. Several critical parameters influence the design of a culvert and its surrounding environment.Amongthese,theflowconditionsandthemanagementofwaterlevelsatboththeinletandoutlet areessentialfortheculvert’soperation,particularlyregardingitsperformanceduringfloodevents.Thisarticle examinestheimpactofvariationsinthelongitudinalslopeoftheculvertandtheelevationofthedownstream bed—bothwithandwithoutanapron—ontheflowprofileenteringandexitingtheculvert.Toinvestigatethis,a series of 80 experiments were conducted in a straight laboratory channel under steady flow conditions. The objectiveofthesetestsistoanalyzethewaterlevelprofilesbothupstreamanddownstreamoftheculvertunder variousscenarios.Theresultsindicatedthatincreasingtheculvertslopeledtoariseinwaterlevelontheupstreamsideoftheculvert.Specifically,themaximumwaterlevelupstreamincreasedby14%,56%,and65.1% whentheculvertslopewasraisedfromzeroto2.5%,4%,and5.5%,respectively.Additionally,theminimum waterlevelupstreamalsoincreasedby19.1%,70.6%,and83.1%underthesameslopechanges.Theaverage maximum and minimum water levels for all scenarios were calculated and compared. The findings of this researchwillbevaluableforanalyzingwatertransferbothupstreamanddownstreamoftheculvertstructure,as wellasforenhancinghydrauliccalculationsrelatedtoitsperformance.