Granular Materials in Civil Engineering: Recent Advances in the Physics of Their Mechanical Behavior and Applications to Engineering Works - Multiscale Geomechanics: From Soil to Engineering Projects - page 51

In other words, the predicted evolution converges towards the progressive
formation of what is usually called the “failure line” (see Figure 3.8b).
Figure 3.8. Localization process
3.1.4. Conclusions
This representation of granular media as a set of simple contact points by means
of the concept of internal actions allows us to predict a large number of properties