• Corpus ID: 235605954

Unsaturated wet granular flows over a rough incline: frictional and cohesive rheology

@inproceedings{Deboeuf2021UnsaturatedWG,
  title={Unsaturated wet granular flows over a rough incline: frictional and cohesive rheology},
  author={St{\'e}phanie Deboeuf and Abdoulaye Fall},
  year={2021}
}

• S. Deboeuf, A. Fall
• Published 23 June 2021
• Geology

must not spill onto p.2 ar X iv :2 10 6. 12 25 8v 1 [ co nd -m at .s of t] 2 3 Ju n 20 21 2 S. Deboeuf and A. Fall the addition of a small amount of liquid in a granular medium creates cohesion properties due to the surface tension of the wetting liquid, which forms pendular bridges attracting grains to their close neighbours. Such a mixture of grains, liquid and air may have a strong solid-like behaviour (Strauch & Herminghaus 2012) that enables the building of sand castles as opposed to dry sand which cannot stabilize under gravity with slopes steeper than the angle of repose (Fiscina et al. 2012; Bocquet et al. 1998). Due to the very high solid fraction of grains in such materials, direct inter-grains contacts play an important part in the physical mechanisms ruling their rheological behaviour, which is strongly influenced by the shape, surface and material properties of the grains (roughness, friction, elasticity, ...). To those micromechanical features, one should add the physical characteristics of the liquid (its viscosity and surface tension, ...) and geometrical microstructural information(Mitarai & Nakanishi 2012; Scheel et al. 2008; Badetti et al. 2018b). Starting from what is done for a frictional granular flow (MiDi 2004; Da Cruz et al. 2005; Andreotti et al. 2013), dimensional analysis of a frictional cohesive granular flow described by the shear, normal and cohesion stresses τ, P and τc , the shear rate ¤ γ and the material properties ρ and d, the mass density and grain diameter respectively, leads to the identification of three dimensionless parameters, defined as: