New approach to describe hydro-mechanical phenomenon of suffusion: erosion, transport and deposition. Issue 14 (5th December 2020) - Abdou, Hashem
Abstract: The phenomenon of suffusion corresponds to the migration of eroded particles in a porous media under the action of an internal flow. This mechanism could be the main origin of damage in embankments and earth dams. Many experimental studies have been conducted to understand this phenomenon. Numerically, only few studies can be found which associate the mechanisms of detachment, transport and deposition of eroded particles. In this paper, based on the classical erosion law, a new hydro-mechanical approach at the scale of a representative elementary volume is presented. The model takes into account the notions of erosion mechanism and deposition mechanism by gravitational sedimentation. These mechanisms are separated, characterised and classified by flow velocity thresholds of each one. However, a finite element solution to the equations will predict the time-dependent change of porosity and flow rate of eroded particles through the pores. The model performed using the software 'COMSOL multiphysics', explicitly combines erosion, transport and deposition of eroded particles. This study discusses three aspects: the general framework of the proposed model, a numerical calibration based on a 3D modelling of a new apparatus called Cross Erosion Test (CET) and finally a simulation based on CET experimental results.