Mechanisms of internal friction in soils and rocks

Abstract

The authors analyse the different mechanisms causing internal friction in soils and rocks, due to surface friction, wedge, rotation and rolling effects. From the kinematics of these mechanisms relations are obtained between the resulting angles of friction, the shapes of soil particles and rock blocks, and the shear displacement. Relations between shear dilatancy and shear displacement are also presented. From the basic mechanisms, the authors derive relations for some combined mechanisms, in special rotation plus surface friction.