Influences of grain shape and size distribution on permeability

Abstract

The present study investigates the effects of shape and size distributions of grains on the coefficient of permeability (k). A series of constant head permeability tests were performed to characterize the coefficient of permeability. Three grain size ranges (4.75-0.075, 1.18-0.075 and 0.300-0.075 mm) of two different sands (Narli Sand, Crushed Stone Sand) having different shapes were tested in a constant head permeability testing apparatus at a relative density (Rd) of about 35% and, a constant room temperature (20°C). Some physical properties of the sands employed, such as median particle diameter (D50), effective particle diameter (D10) coefficient of uniformity (cu), and coefficient of curvature (c c), were the same for these two sands. Experimental results showed that the coefficient of permeability values of Crushed Stone Sand (CSS) was higher than those of Narli Sand (NS). Empirical equations derived by numerous researchers for the coefficient of permeability prediction have been implemented on the estimated permeability values obtained from the laboratory. © 2015 Taylor & Francis Group.