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Collapse tests

The collapse test is a simple experimental test to evaluate the flowability of materials and an excellent benchmark for the numerical modelling community for validating numerical models.

Several collapse tests were carried out in our laboratory and modelled with DEM, DEM-PFV and SPH.

Experimental tests

Experimental test campaigns were performed in quasi-2D conditions (column) as well as in axial-symmetric conditions with different granular materials, water contents and aspect ratios.

For glass balls see

For angular carbonate particles and glass balls see

For mixture of cohesive and granular materials see

DEM numerical simulations

DEM is straightforward for modelling glass balls in dry and wet conditions.

A capillary force at the contact between grains was implemented in DEM

These are some results showing the difference between the dry (Figure 1) and wet conditions (Figure 2).

Figure 1: DEM simulations of glass ballotini (D= 2mm) in dry conditions
Figure 2: DEM simulations of glass ballotini (D= 2mm) mixed with water (water content = 1%)


Gabrieli, F., Artoni, R., Santomaso, A., & Cola, S. (2013). Discrete particle simulations and experiments on the collapse of wet granular columns. Physics of Fluids, 25(10).
Santomaso, A. C., Volpato, S., & Gabrieli, F. (2018). Collapse and runout of granular columns in pendular state. Physics of Fluids, 30(6), 63301.
Brezzi, L., Gabrieli, F., & Cola, S. (2020). Collapse of granular–cohesive soil mixtures on a horizontal plane. Acta Geotechnica, 15(3), 695–714.