Geotextiles in Embankment Dams - Association of State Dam Safety ...

Geotextiles in Embankment DamsFigure 2.27.—Knitted multifilament geotextile, magnified view (1 mm scale).2.11 Geotextile related productsGeotextile Related Products are generally geosynthetics that are either much thicker,coarser in structure or combined multilayers of the previously described geotextilesand other geosynthetics (also referred to as geocomposites). These types of productseither utilize a geotextile or are composed of geotextiles and hence are related to thefunctional groups described in the introduction. Examples of geotextile relatedproducts are geomats with a geotextile attached for filtration, geonet compositeswhich are geonets with a geotextile attached to one or both sides, geodrains whichinclude a geotextile wrap or facing for filtration, woven/nonwoven geotextilecomposites, nonwoven/coarse nonwoven geotextile composites,geotextile/geomembrane composites and virtually all erosion control materials.The most common geotextile related products in embankment dam construction arethose which provide combinations of functions such as filtration and drainage,protection, hydraulic barrier and drainage and surface reinforcement with filtration.Examples are as follows:Filtration/Planar Drainage. A geonet composite (geonet with nonwoven geotextileon both sides) or a geomat with geotextiles provides a toe drain drainage blanketfunction by filtering the embankment soils away from the internal planar drain torelieve pore water pressures.42