Crib Dam

Crib Dam

 

a wooden or, sometimes, reinforced-concrete water-retaining structure whose basic load-bearing elements are cribs. Crib dams usually withstand pressures to 10–15 m (sometimes up to 20 m). Despite the limited durability of wood, crib dams made out of such material are very economical, especially in heavily forested regions. In reinforced-concrete crib dams both the upstream and downstream faces are solid reinforced-concrete slabs; the space between the slabs is filled with ballast (earth, stones). Considerably less concrete is used in a reinforced-concrete crib dam than in a large gravity dam. Crib dams are erected, as a rule, directly on rocky foundations and other foundations in which it is impossible to drive pilings. In some crib dams, however, the cribs are supported by piles.

References in periodicals archive ?
According to the city of Ketchikan, a timber crib dam was initially built on Whitman Lake in 1912.
The size of individual thalli was estimated based on the number of somatically compatible isolates from each sampled crib dam (Worrall 1997).
Nevertheless European white fir is ranked as more durable than Norway spruce by Knigge and Schulz (1966), and forest practicioners in Switzerland frequently regard European white fir more durable than Norway spruce in crib dam constructions (Zeller 1987, Rickli 1997).
The colonization of various crib dam sections by basidiomycetes reflects their sensitivity to water logging.
Therefore, replacement of single weakened crib dam components can significantly increase the life span of these constructions, thereby supporting earlier recommendations.
Parameters considered in the statistical model to explain decay in wooden crib dam components.
Wooden crib dams are widely used for torrent control in mountainous regions.
Crib dams provide a specific habitat for fungi due to the use of fresh logs for construction, soil contact and fluctuating moisture.
The community's ties to it go back to 1858, when industrialists built a wooden crib dam to divert water into the Brownsville millrace, Mayor Don Ware told an audience of nearly 100.
A wooden crib dam was the first dam built on the falls in 1853.
Loggers would build wood crib dams on streams, pile logs in the pooling water behind them - then blow up the dams to float the logs down to the sawmills.