Design standards No. 13 : Embankment Dams. Chapter 5 - Protective Filters

Chapter 5 – Protective Filters is an existing chapter within Design Standards No. 13 and was revised to include: Addition of historical perspective and mechanics of particle retention; Addition of zone interface considerations; Revised gradation selection procedure, especially base soil selection; Revised pipe perforation criteria; Addition of laboratory procedures for gradation and material quality; Addition of construction considerations.

Filters and drains have been recognized as a means of directing and controlling the flow of water through porous media for thousands of years; the earliest documented use of drains is at the Ur of the Chaldees. Filters are used to prevent migration of fines between various zone s and foundations of embankment dams. Seepage transport of soil particles between zones can lead to serious consequences and, in extreme cases, failure of an embankment dam. The criteria presented in this chapter are for guidance in the proper design of soil filters, drains, and zoning of embankment dams.