Technical Manual: Conduits through Embankment Dams (FEMA 484)

GlossarySettlement (FEMA, 2004): The vertical downward movement of a structure or itsfoundation.Shear strength (ASCE, 2000): The ability of a material to resist forces tending tocause movement along an interior planer surface.Shear stress: Stress acting parallel to the surface of the plane being considered.Shore (ACI, 2000): A temporary support for formwork and fresh concrete.Silt (ASTM D 653, 2002): Material passing the No. 200 (75-µm) U.S. standard sievethat is nonplastic or very slightly plastic and that exhibits little or no strength whenair-dried.Sinkhole: A depression, indicating subsurface settlement or particle movement,typically having clearly defined boundaries with a sharp offset.Siphon: An inverted u-shaped pipe or conduit, filled until atmospheric pressure issufficient to force water from a reservoir over an embankment dam and out of theother end.Slaking: Degradation of excavated foundation caused by exposure to air andmoisture.Sliplining: The process of inserting a new, smaller-diameter lining or pipe into anexisting larger-diameter conduit.Slope (FEMA, 2004): Inclination from the horizontal. Sometimes referred to asbatter when measured from vertical.Slurry: A mixture of solids and liquids.Soil (ASTM D 653, 2002): Sediments or other unconsolidated accumulations ofsolid particles produced by the physical and chemical disintegration of rocks, andwhich may or may not contain organic matter.Soil resistivity: The measure of the resistance to current flow in a soil.Soluble salt: A salt that can be dissolved in water.Sonar: A geophysical method which measures the reflection of acoustic waves tomap underwater structures. Often refers to side-scan radar.415