Filter, Graded

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Filter, Graded

 

a device in headworks that consists of several layers of unconsolidated material with increasingly coarse particles in each layer. The material may be sand, gravel, rubble, or pebbles; the coarseness of the particles increases toward the seepage line. Graded filters are used mainly in earth dams and other hydraulic-engineering installations erected on soft foundations. Such filters prevent seepage from washing fine soil particles from the body and base of the installation.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.