Application of fractal dimensions to examine the frictional behavior of granular materials

This paper aims to investigate the key factors affected on the shear frictional behavior of granular materials. In this study, a box dimension to describe the grain gradation is obtained from the grain size distribution curve of a sieve analysis result according to the fractal theory. A cluster dimension for describing the degree of grain packing is got by the radius-number method. In the other hand, the sample of coarse grains mixed with the matrix material (a mixture of plaster and sand) is sheared. Therefore, the connection between the granular materials and its fractal dimensions is to be examined. This paper finds that the shear friction angle of granular materials is mainly controlled by its gradation. The well-graded collection, which has a higher box dimension, will have a larger friction angle.