DYNAMIC LAYERED MODEL
OF SUBMARINE SEDIMENT SLIDE

Stress-strain dependence for sedimentsDistribution of friction angles used for calculation ___________________

II stage: Taking into account 1) rheological effect of decreased sediment mass strength above yield stress; 2) porous saturation of sediment mass; 3) possibility of landslide masses liquefaction under condition of any external action. The key factor which controls the localisation process of plastic strain and related slope instability is a friction angle.

[1] Garagash I.A., Lobkovsky L.I., Kozyrev O.R., Mazova R.Kh. Generation and runup
of tsunami wave under submarine landslide. Oceanology 43, 173-181 , 2003.
[2] Garagash I.A., Chemenda A. Numerical modeling of submarine landsliding triggered by seismic and tectonic processes. in: Proc. of 2nd Taiwan-France Symposium on Natural Hazards Mitigation: Methods and Applications, Villfranche-sur-Mer (SE France), 2003.

Notes: In this case, to calculate the landslide-generated tsunami run-up on a beach, a dynamical layered model of submarine sediment slide is used.

There are two stages in simulation of landslide motion.

Fig. a. At the first stage, a simulation of initial, preliminary stressed state of slope with sediments is performed, formatted under action of its own weight and saturation with the water under sea pressure. Note, that this stage, in fact, is absent in usual basic models.

Fig. b. At the second stage, simulation is performed taking into account

1. rheological effect of decrease sediment mass strength above yield stress
2. porous saturation of sediment mass
3. possibility of landslide masses liquefaction under conditions of any external action.

The key factor which control the localisation process of plastic strain and related slope instability is a friction angle. Here, you can see the distribution of two angles used in calculations.