Static and dynamic arching effect in granular materials

The arching effect has been recognized as a characteristic feature of granular materials. Recent studies have proved that, under peculiar circumstances, granulates build up inner solid contact chains which greatly influence the flow behavior and sometimes turn out to prevent any gravity-induced motions, such as falls. Mostly based on experimental observations of vertical chutes, this paper attempts to outline basic principles which govern the stability and the behavior of both static and dynamic arches.