Friction Angles of Sands: An Appraisal

Abstract

River sand is a naturally occurring conventional construction material, which has good frictional properties.Due to a steep rise in the construction activities all over the world, natural sand resources are getting depleted. This has favored / forced the construction industry in general and geotechnical engineering practice in particular to go for M-sands. This necessitates a proper understanding of the frictional characteristics of Msands. In this technical note, the results from a comparative study of the friction angles of river sand and Msand with reference to the effect of grain size, grain angularity, dry density and gradation are reported. It is shown that M-sand exhibits higher friction angles than river sand at minimum density levels and river sand exhibits higher friction angles than M-sand at maximum density levels, on average, irrespective of grain size. It is also shown that poorly graded M-sands exhibit higher friction angles than well graded M-sands at minimum density levels, whereas well graded river sands have higher friction angles than poorly graded river sands irrespective of density levels.