Technical Manual: Conduits through Embankment Dams (FEMA 484)

Conduits through Embankment DamsBond (ACI, 2000): Adhesion and grip of concrete or mortar to reinforcement or toother surfaces against which it is placed, including friction due to shrinkage andlongitudinal shear in concrete engaged by the bar deformations.Borehole: Any exploratory hole drilled into an embankment dam or its foundationto gather geophysical data.Breach (FEMA, 2004): An opening through an embankment dam that allows theuncontrolled draining of a reservoir. A controlled breach is a constructed opening.An uncontrolled breach is an unintentional opening caused by discharge from thereservoir. A breach is generally associated with the partial or total failure of theembankment dam.Buckling: Failure by lateral or torsional instability of a conduit, occurring withstresses below the yield strength.Bulkhead gate: See Gate, bulkhead.Bulking: The low density condition in a fine sand that occurs when negativecapillary stresses develop when the sands are placed at intermediate water contents.Sands placed at a bulking water content have a much lower density than those placedvery dry or saturated. Sands that may have been placed at a bulking water contentmay be densified by flooding and vibratory compaction.Calibration hose (ASTM F 1743, 1996): An impermeable bladder, which isinverted within the resin-impregnated fabric tube by hydrostatic head or air pressureand may optionally be removed or remain in place as a permanent part of theinstalled cured-in-place pipe.Caliper: An instrument used to measure the diameter of a conduit.Caliper measurements: Measurement of the internal dimensions of a conduit,either by a physical device or by reflection of acoustic waves from a sled or cart.This method can be used to locate areas of conduit corrosion or excessivedeformation.Camera-crawler: A video camera attached to a self-propelled transport vehicle(crawler). Typically, the camera-crawler is used for closed circuit televisioninspection of inaccessible conduits.Canal: A channel that conveys water by gravity to downstream users.Cast-iron pipe: See Pipe, cast-iron.392