Meaning of DAM in English


A structure of earth, rock, or concrete designed to form a basin and hold water back to make a pond, lake, or reservoir. A barrier built, usually across a watercourse, for impounding or diverting the flow of water. General types of dams include: (1) Arch Dam: Curved masonry or concrete dam, convex in shape upstream, that depends on arch action for its stability; the load or water pressure is transferred by the arch to the Abutments. (2) Buttress Dam: A dam consisting of a watertight upstream face supported at intervals on the downstream side by a series of buttresses. (3) Cofferdam: A temporary watertight enclosure that is pumped dry to expose the bottom of a body of water so that construction, as of piers, a dam, and bridge footings, may be undertaken. A "diversion cofferdam" prevents all downstream flow by diverting the flow of a river into a pipe, channel, or tunnel. (4) Crib Dam: A barrier or form of Gravity Dam constructed of timber forming bays, boxes, cribs, crossed timbers, gabions or cells that are filled with earth, stone or heavy material. (5) Embankment Dam: A dam structure constructed of fill material, usually earth or rock, placed with sloping sides and usually with a length greater than its height. Types of embankment dams include: Earthfill or Earth Dam: A dam in which more than 50 percent of the total volume is formed of compacted fine-grained material obtained from a borrow area (i.e., excavation pit); Fill Dam: Any dam constructed of excavated natural materials or of industrial waste materials; Homogeneous Earthfill Dam: A dam constructed of similar earth material throughout, except for the possible inclusion of internal drains or drainage blankets; distinguished from a Zoned Earthfill Dam; Hydraulic Fill Dam: A dam constructed of materials, often dredged, that are conveyed and placed by suspension in flowing water; Rockfill Dam: A dam in which more than 50 percent of the total volume is comprised of compacted or dumped pervious natural or crushed rock; Rolled Fill Dam: A dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment; and Zoned Embankment Dam: A dam which is composed of zones of selected materials having different degrees of porosity, permeability, and density. (6) Gravity Dam: A dam constructed of concrete and/or masonry that relies on its weight for stability. (7) Masonry Dam: A dam constructed mainly of stone, brick, or concrete blocks that may or may not be joined with mortar. A dam having only a masonry facing should not be referred to as a masonry dam. (8) Weir: A dam in a river to stop and raise the water, for the purpose of conducting it to a mill, forming a fishpond, or the like. When uncontrolled, the weir is termed a fixed-crest weir. Other types of weirs include broad-crested, sharp-crested, drowned, and submerged.

Environmental engineering English vocabulary.      Английский словарь экологического инжиниринга.