Search results
Results from the WOW.Com Content Network
Commonly, weirs are used to prevent flooding, measure water discharge, and help render rivers more navigable by boat. In some locations, the terms dam and weir are synonymous, but normally there is a clear distinction made between the structures. Usually, a dam is designed specifically to impound water behind a wall, whilst a weir is designed ...
Charpy test sample with a notch. In mechanical engineering and materials science, a notch refers to a V-shaped, U-shaped, or semi-circular defect deliberately introduced into a planar material. In structural components, a notch causes a stress concentration which can result in the initiation and growth of fatigue cracks.
A free nappe, which is ventilated to maintain atmospheric pressure below, does not come into contact with the underside of the weir. [7] A depressed nappe is partially ventilated, which creates negative pressure beneath the nappe. The negative pressure leads to a 6% to 7% increase in discharged water compared to a free nappe. [8]
Gabion stepped weirs are commonly used for river training and flood control; the stepped design enhances the rate of energy dissipation in the channel, and it is particularly well suited to the construction of gabion stepped weirs. [2] A gabion wall is a retaining wall made of stacked stone-filled gabions tied together with wire.
Stoplogs are frequently used to temporarily block flow through a spillway or canal during routine maintenance. At other times stoplogs can be used over longer periods of times, such as when a field is flooded and stoplogs are being used in smaller gates in order to control the depth of water in fields.
Block on a ramp and corresponding free body diagram of the block. In physics and engineering, a free body diagram (FBD; also called a force diagram) [1] is a graphical illustration used to visualize the applied forces, moments, and resulting reactions on a free body in a given condition. It depicts a body or connected bodies with all the ...
Log fences or split-rail fences were simple fences constructed in newly cleared areas by stacking log rails. Earth could also be used as a fence; an example was what is now called the sunken fence , or "ha-ha," a type of wall built by digging a ditch with one steep side (which animals cannot scale) and one sloped side (where the animals roam).
Beamless tilting weirs are used where the watercourse could be subject to a significant volume of debris. Small boats and canoes are able to cross a beamless weir. Tilting weirs are manufactured from galvanized mild steel, painted mild steel, stainless steel, HDPE and set in channels which are likely to be reinforced with concrete.