Spreading of Kaolin and Sand Mixtures on a Horizontal Plane: Physical Experiments and SPH Numerical Modelling

The investigation of the collapse of a well-known soil volume is a simple experiment that permits to make several interesting considerations. This paper, at first, presents a brief overview of some physical experiments led to understand how the composition of a three-phase mixture influences the mass collapse. In particular, the run-out and the maximum height of the deposit are considered as two fundamental quantities for characterizing the behaviour of the mass in each test. In a second step, the experimental results obtained are used as case studies for the calibration of a mesh-less numerical model. Several simulations are carried out using the SPH-Geoflow code implementing a Bingham law to reproduce each bi-phases test. A comparison between the numerical results and the physical data permits to choose the most reliable value of the constitutive parameters for each tested case. The errors between the physical and the numerical run-out and maximum heights become the fundamental quantity to define the quality of the best simulation. Indeed, some final considerations about the relationship existing among the constitutive parameters and the kaolin content of the mixtures are reported.