Abstract:
Particle breakage plays an important role in rockfill mechanical behaviour.
Under compression or shear, the crushing of particles modifies the grain size distribution
and indirectly, the material permeability, their frictional properties and the corresponding
critical state. In order to study the breakage of individual particles, several approaches
were adopted using discrete element method (DEM). Some considered sub-particles joined
by bonding or cohesive forces, other replaced particles, which verified a predefined failure
criterion, by an equivalent group of smaller particles. In this paper, using the discrete
element method, a new methodology was developed. It consisted of modelling crushable
rockfill particles using the clump logic, which was responsible for providing a statistical
and spatial variability in the strength and shape of the particles. Particle movements
and interactions were determined using DEM, allowing to determined the deformation of
the rockfill material. Clumps have a major advantage of severely decreasing the num-
ber of contact equations to be solved in the model, resulting in less computer time. A
comprehensive study of the brittle failure of single-particle crushing tests is presented.
Preliminary tests on particle size evolution were also performed, assuming some simplifi-
cations. No attempt was made to simulate the real particle size distribution (PSD), due
to the cost of simulating smaller particles. Single-particle crushing tests and oedome-
ter tests were simulated using crushable particles, whose results were in agreement with
experimental data.
