Shaft Spillway

shaft spillway

[′shaft ′spil‚wā]
(civil engineering)
A vertical shaft which has a funnel-shaped mouth and ends in an outlet tunnel, providing an overflow duct for a reservoir. Also known as morning glory spillway.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Shaft Spillway

 

in hydrotechnics, an automatic tubular spillway used chiefly to discharge excess water from reservoirs with dams, from canals, and from the head basins of hydroelectric power plants. The inlet of a shaft spillway is usually flared and is submerged below the level of the head in order to prevent the entrapment of air, litter (such as driftwood), and ice. The advantages of a shaft spillway include the large carrying capacity and the feasibility of constructing the spillway after the main construction has been completed, for instance, in the event it becomes necessary to expand the spillway facilities.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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References in periodicals archive ?
Shaft spillway is one of the spillway types used to pass additional waters and floods from the upstream to the downstream of dams.
Keywords: Shaft spillway, Discharge coefficient, Submergence, flow pattern
Shaft spillway is a spillway composed of a circular crest that directs the flow to an inclined or vertical axis, which is connected to a low gradient tunnel.
One of the major water conveyance structures that can act as an emergency spillway is shaft spillway. This type of spillway is so effective when there is not adequate space to build other types of spillways.
In this chamber, which is like a metal mesh screens, a series of straw was used to slow the flow that the water passes through the second buffer and entered the reservoir of the shaft spillway. The reservoir of the shaft spillway is sizes 1.2 x 1.1 x 1.2 meter which is completely enclosed from three sides and on the other hand, to observe the phenomenon inside the reservoir, a glass sheet with a thickness of 10 mm and a scale connected to reservoir glass was used to measure the height of the water on the shaft spillway.
To compare sharp triangular vortex breaker blades with rectangular body according to Figures (2) and (3) on the efficiency of the discharge of shaft spillway, 6 vortex breakers in three different lengths of 10, 15 and 20% of the overflow diameter with a thickness of 2 cm and a height of 4 cm m are used.
--bigger cracks, deformation, tilt in shaft spillway 33 ED (12.7%);
The same amount of deformation, tilt in shaft spillway has been registered in Lithuanian dams (12.7%).
The shaft spillway is one of the spillways used in the dams.
Through experimental investigation of the effect of the bend arc radius on shaft spillway flow hydraulic, Youssefvand et al.