Modellazione fisica dei processi di instabilità di sponde fluviali ghiaiose

During recent years, many progresses have been made in understanding and modelling bank erosion, however numerous problems and aspects are still not understood. In particular, the mechanisms of bank instability in relatively coarse riverbanks (mainly composed by gravel) represents an area that needs further investigation. The objective of this research is to obtain a better comprehension of the basic processes occurring in relatively coarse bank sediments, in particular the occurrence of mass instability in the absence of fluvial erosion. A physical model of a bank composed by granular relatively coarse sediment has been built, and a first experiment simulating the behaviour of the bank during a hydrograph has been carried out. Preliminary results of this experiment are reported in this presentation, with a discussion of the observed mechanisms of failure and relative causes.