ABSTRACT
In all cases compaction bands were found to form approximately in a direction perpendicular to the principal stress. In almost all cases they formed close to the top or bottom boundaries of the specimen. This is because the different contact force conditions, with lower coordination numbers and a less dense soil fabric, favour initiation of localisation in these zones. Vaidova & Wong (2003), however, reproduced internal compaction bands by inserting a circumferential notch (as a defect) in their sandstone specimens.
