Earthen Dam


Also found in: Dictionary, Thesaurus, Medical, Legal, Financial.

Earthen Dam

 

a dam built of soil materials (sand, loam, clay, and so on), with a trapezoidal or nearly trapezoidal cross section. Earthen dams are usually of the fixed type (without the flow of water over the crown); they are commonly used in many countries because of their simplicity of construction and maintenance. Six main types of earthen dams are distinguished, depending on the materials used for the body of the dam and the methods of providing waterimpermeability.

Earthen dams may be built on virtually any type of ground base (except strongly liquescent muddy soil). The watertight part of the dam (the baffle and core) is usually joined to the rocky base by a cutoff or a concrete joint tongue, under which a grouted cutoff is set in fissured rock. On a nonrock base, if the water-resistant material (clay or rock) is located at an acceptable depth, the impermeable part of the dam is joined to the water-resistant material by a positive ground cutoff, a sheet pile bulkhead, or a curtain (partial cutoff). A blanket or partial cutoffs and a sheet pile bulkhead, are installed for a deep-lying water support.

Earthen dams are distinguished according to their construction method as fill dams, which are built up by dry pouring of soil, with artificial consolidation and without consolidation (with pouring of the soil into the water or by means of a directed explosion), and hydraulic fill dams, the construction of which (the aggradation of the body of the dam) is accomplished by the hydromechanization method. The drainage of an earthen dam is usually made in the form of a drainage shell or a drainage mattress buried in the body of the dam. Rock fill and paving stone facing covered with concrete or reinforced-concrete slabs are used to protect the upstream (pressure) slopes of earthen dams against wave action. The downstream slopes are protected by planted grass, turf, poured gravel, and crushed stone. Modern mechanical excavation methods make possible the construction of earthen dams to heights of 150 m or more.

REFERENCES

Grishin, M. M. Gidrotekhnicheskie sooruzheniia. Moscow, 1968. Stroitel’stvo, vol. 1. Moscow, 1964.(Entsiklopediia sovremennoi tekhniki.)

P. N. KORABLINOV

References in periodicals archive ?
Of current concern to the Stillwater lab are the nation's earthen dams. America's countryside is dotted with these small dams.
Fayard were under the impression, based on the 2006 state report, that only minimal work was needed on the earthen dam, but Mr.
The National Geographic, in a 2015 article that examined the failure of earthen dams, suggested four reasons for their failuresmdash top among them being too much rainfall over a short period.Mr David Adede, a geologist, agrees.
FWO is an organization working for developmental engineering in Pakistan that includes tunneling, earthen dams, the construction of bridges and roads among other things.
The dam, one of the world's longest earthen dams, is built across the Mahanadi River, which is about 15 kilometers from Sambalpur District.
His work has contributed to the development of model components used in computer software-SITES-for evaluating earthen spillways on dams, and WinDAM for evaluating overtopping and erosion of earthen dams. He also developed the concepts, equations, equipment and methodology for the Jet Erosion Test for characterizing erodibility of soils.
9 February 2010 - Indian credit rating agency CRISIL assigned ratings of BB+ with a "stable" outlook and of P4+ to various bank facilities of local earthen dams and canals builder LB Kunjir.