Strength of a carbonate silt at the solid fluid transition and submarine landslide run out
Submarine landslide run out is governed by the rheology of the sediment as it evolves from a soil to a viscous fluid. It has been shown previously that the geotechnical characterization of fine grained sediments can be extended into the liquid range in a continuous fashion (Boukpeti et al. 2012) In this paper, we present the results of strength measurements on a carbonate silt over a wide range of water contents and compare them with results reported previously for two other soils.We then show that a reasonable estimate of submarine slide run out can be obtained from a simplified analysis based on the energy dissipation through sliding at the base of the slide. Results of the simplified analysis are validated through comparison with run out predictions obtained using the one dimensional depth averaged modelling softwareUWA SM3. Using a simple formulation to account for water entrainment in the run out analysis, the influence of the soil rheology on the final run out is demonstrated. In this case, difference in the rheology of the carbonate silt compared to the non carbonate fine grained soils leads to a stronger influence of water entrainment on run out distance.