COMPACTION OF SAND--COHESIONLESS SOIL

Compaction is the act of artificially densifying or increasing the unit weight of soil through the application of external forces, thereby reducing the voids or pore spaces to a minimum and increasing the solid particle content to a maximum. The aim of compaction is the improvement of engineering properties of soil such as: an increase in shear strength and bearing capacity; a decrese in volume changes and settlement; and a decrease in permeability and ingress of water. Compaction is measured in terms of dry density achieved. This paper discusses compaction for cohesionless soils such as sand and gravel, wherein the compaction curves of the moisture-density relationship are often much flatter, with the maximum dry density being low or with no pronounced peak at all.