From Particle to Material Behavior: the Paths Chartered by Jean Biarez - Multiscale Geomechanics: From Soil to Engineering Projects - page 29

Figure 2.16. Influence of grading on the percentage of broken blocks during the
numerical simulation of a biaxial test, material 31 being narrowly graded and
material 32 being broadly graded (from [DEL 04])
The increase in compressibility during an oedometer test (Figure 2.17) and the
decrease in dilatancy during a biaxial test linked to particle breakage were also found
by means of these numerical simulations by discrete elements. Moreover, they showed
that, during a biaxial test, the value φ of the peak friction angle decreases with the
logarithm of the confining pressure when this pressure increases (Figure 2.18).
Figure 2.17. Effect of the breakage of blocks on the slope of the compressibility curve during
the numerical simulation of an oedometer test with materials of different strengths:
η inc (unbreakable material), η Gn (moderately resistant material)
and η fra (weakly resistant material) (from [DEL 04])