Experiments and modelling of cantilever failures for cohesive riverbanks

Abstract

ABSTRACTThis paper presents experiments and modelling of cantilever failures for a cohesive riverbank. Two types of cohesive materials with different bank cohesions were investigated under similar hydraulic conditions to clarify and simulate the failure phenomena. The experimental results showed that fluvial erosion undermined the banks during the initial stage of failure, and tension cracks then developed at the upper surface of the banks. Beam failure occurred thereafter. Additionally, a numerical model was developed using a triple-grid approach to simulate the behaviour of a cantilever within the framework of fluvial erosion, cantilever failure, slump block, and sediment transport. Moreover, cantilever failure was analysed using a limit equilibrium method to compute the stability of the overhanging block. The numerical model exhibited good agreement with the experimental results in terms of the spatial-averaged bank width along the banks and of the dominant failure type, which was beam failure.