Search results
Results from the WOW.Com Content Network
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.
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.
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 ...
Concrete check dams in Austria A steel check dam A common application of check dams is in bioswales, which are artificial drainage channels that are designed to remove silt and pollution from runoff. A check dam is a small, sometimes temporary, dam constructed across a swale , drainage ditch , or waterway to counteract erosion by reducing water ...
A steel fence post, also called (depending on design or country) a T-post, a Y-post, or variants on star post, is a type of fence post or picket. They are made of steel and are sometimes manufactured using durable rail steel. They can be used to support various types of wire or wire mesh.
A drop structure, also known as a grade control, sill, or weir, is a manmade structure, typically small and built on minor streams, or as part of a dam's spillway, to pass water to a lower elevation while controlling the energy and velocity of the water as it passes over.
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.
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]