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

Geotextiles in Embankment Damsembankment dams and foundation, except for the specific process referred to as“backward erosion piping.” The term “internal erosion” is used in this document inplace of a variety of terms that have been used to describe various erosionalprocesses, such as scour, suffusion, concentrated leak piping, and others.Internal Friction (shear resistance) (FL -2 ) (Frobel, 1987): The portion of theshearing strength of a soil or rock indicated by the terms p tan φ in Coulomb’sequation s = c + p tan φ. It is usually considered to be due to the interlocking of thesoil or rock grains and the resistance to sliding between the grains.Isotropic Material (ASTM D 653, 2005): A material whose properties do not varywith direction.Laboratory sample (ASTM D-4439, 2004): n – a portion of material taken torepresent the lot sample or the original material, and used in the laboratory as asource of test specimens.Laminar flow (ASTM D-4439, 2004): n – flow in which the head loss isproportional to the first power of the velocity.Laminate (Frobel, 1987): A produce made by bonding together two or morelayers of material or materials.Leakage (FEMA, 2004): Uncontrolled loss of water by flow through a hole orcrack.Lining (FEMA, 2004): With reference to a canal, tunnel, shaft, or reservoir, acoating of asphaltic concrete, reinforced or unreinforced concrete, shotcrete, rubberor plastic to provide watertightness, prevent erosion, reduce friction, or support theperiphery of the outlet pipe conduit.Lot (ASTM D-4439, 2004): n – a unit of production, or a group of other units orpackages, taken for sampling or statistical examination, separable from other similarunits.Lot sample (ASTM D-4439, 2004): n – one or more shipping units taken atrandom to represent an acceptance sampling lot and used as a source of laboratorysamples.Machine direction (ASTM D-4439, 2004): n – the direction in the plane of thefabric parallel to the direction of manufacture.Mastic: A permanently flexible waterproofing material used for sealing watervulnerablejoints.168