Investigation approaching flow to bridge and prediction of bridge pier scour with floodplain vegetation in compound channels under pressurized flow conditions

Abstract The local scouring around the pier, is one of major cause bridges failure worldwide. Compared to flow hydraulics in single channels, pattern compound channels completely different with flood plains covered vegetation and this issue can affect amount area bridge piers. However, combined effect these factors has not been systematically investigated. Therefore, due complex nature phenomenon absence an accurate prediction model, research, experimental study on hydraulic characteristics approaching deck floodplain pressurized conditions, done. It was found that increasing density average will reduce scour depth by 15% for same width relative depth. In free-flow increase aim develop optimized model estimate pier consideration effect. newly developed relationship shows a good correlation coefficient more than 92% data yielded better results previous equations. finding have potential applications clear water conditions.