DILATATION IN DIRECT SHEAR TESTS OF HONG KONG COMPLETELY DECOMPOSED GRANITE (CDG)

This paper discusses dilatation in direct shear tests. There are 2 types of vertical displacements in direct shear tests. They reflect same dilatation and shrinking behavior of soil as those in triaxial tests. The dilatation is related to the density of soil. The shear stress required for the dilatation increases with the normal stress. The shear displacement for the dilatation is always less than that at the peak shear stress.