Modelling of fast catastrophic landslides and impulse waves induced by them in fjords, lakes and reservoirs

Catastrophic landslides can cause impulsive waves in reservoirs, fjords and other water bodies. This work presents a methodology for modelling such phenomena. We split the analysis into (i) initiation and (ii) propagation of the landslide, (iii) entering of the wave in the water (near field), and (iv) far field propagation. Concerning initiation, we use a coupled model in displacements and pore pressures, together with a suitable constitutive model of the generalized plasticity type describing soil behaviour. Propagation is analyzed with a depth integrated model incorporating the fluidized soil rheology. The third phase – interaction of landslide and water – is modelled with a level set algorithm which keeps track of the interfaces between solid, air and water. Propagation in the far field is performed using a depth integrated model. We will also present the results obtained with a double layer depth integrated model.