A new algorithm for bank-failure mechanisms in 2D morphodynamic models with unstructured grids

Experiments and Numerical Simulations of Dike Erosion due to a Wave Impact

“…The results of the laboratory experimental campaign have been utilized to validate the capability of a numerical model by Greco et al [28] (see also [34,35]) of predicting the physical evidence. The above-described experiments have been reproduced numerically, in order to check if the model could be hereafter reliable for analyzing a greater number of scenarios.…”

“…The model, here used for the simulation of the process, is based on a depth-integrated two-phase approach, under the assumptions of the hydrostatic distribution of pressures, bed load sediment transport and a uniform and non-cohesive sediment, and includes a geo-failure operator [35,36]. Conservation equations of mass and momentum are written for the water and solid phases separately, with a closure relation for the bed deformation rate.…”

“…The operator is based on a limiting slope stability criterion: when in the cell the bed slope exceeds a critical angle, depending on the saturation degree of the sand, the bottom collapse occurs and the corresponding bed material and pore water become available to flow, thus following the two-phase flow dynamics. The algorithm also permits the failure to propagate from the single cell to the entire domain, preserving both the continuity of the bottom surface and the mass conservation [36,39].…”

Numerical Modelling of Cohesive Bank Migration

“…When the slope becomes steeper, for example due to a scour at the bank toe, the sediments begin to slide, forming a new slope. One possible approach is to make slipped material undergo a transition from bed layer to flow current, as suspended load [39]. In the present paper, on the other hand, it has been decided to move the slipped material to the toe of the bank [38], where it can be entrained by the current at a later time.…”

“…Others evaluate a bank erosion/accretion rate, which gives rise to the displacement of bank top and a consequent mesh modification [31,32,[35][36][37] or, in a similar way, they couple a bed scouring with an intermittent bank erosion model, which shift the bank while keeping the same initial angle of repose [28]. Another approach consists in coupling the basal erosion due to hydrodynamic forces with a bank failure model, which triggers when the bank slope exceeds a critical angle [33,34,38,39]. The wide variety of strategies adopted in literature indicates that the issue is still not a closed one.…”