Experimental study on bank failure process and interaction with riverbed deformation due to fluvial hydraulic force

The paper presents a study on non-cohesive and cohesive homogenous bank failure processes,in-fluence of bank failure mass on bank re-collapse as well as the interaction between bank failure and bedevolution through a series of experiments carried out in a 180° bend rectangular flume. The results revealthe iteration cycle between bank erosion and bed deformation;basal erosion due to fluvial hydraulic force,bank failure under the influence of gravity,failure block staying at bank toe temporarily or being remobi-lized by the flow,exchange between bank failure mass and bed material,bed-material load being reworkedor transported either as bed load or as suspended load,and bed deformation. Same as bank failure,themixing of bank failure mass and bed material is more serious near the curved flow apex. Moreover,non-co-hesive bank failure tends to occur near the water surface,while cohesive bank failure near the bank toe.For non-cohesive material,the bank erosion amount and residual amount of bank failure mass on the bedincrease with the near-bank velocity or bed movability. But for cohesive material,only bank erosion amountobeys the above rule. In addition,the research indicates that the mechanism and patterns of bank collapseand interaction between bank failure and bed evolution,which could provide a theoretical basis for further study.