Engineering:Cut (earthmoving)
In civil engineering, a cut or cutting is where soil or rock material from a relative rise (elevated landscape) to an earlier section of the route is cut out to make way for a further section of the route, whether canal, road or railway line. It can also be used in river management to speed the flow of the river, short-cutting a meander.
In cut and fill construction and across uneven terrain it keeps the route straight and/or flat, where the comparative cost, desirability or practicality of alternate solutions (such as an indirect route or the alternatives of embankment or similarly raised viaduct) for the desired incline are prohibitive. In road and rail, cuttings provide low noise pollution relative to the use of at-grade solutions, viaducts or embankments. Contrary to the general meaning of a cutting in construction the term specifically refers to land mechanically excavated, hand-dug or, mainly in mountainous examples, blasted out with explosives.
Cuts may made on the approach to a slope or a cliff which may be tunneled, others directly through the middle or top of a hill or similar relative rise. A cut is by definition open at the top. Where covered it is a cut-and-cover tunnel as opposed to a bored tunnel.
Cuts are typically used to reduce the length and (often more importantly) the grade of a route.
Cuts can be created by multiple passes of a shovel, grader, scraper or excavator, or by blasting.[1] One unusual means of creating a cut is to remove the roof of a tunnel through daylighting. Material removed from cuts is ideally balanced by material needed for fills along the same route, but this is not always the case when cut material is unsuitable for use as fill.
The word is also used in the same sense in mining, as in an open-cut mine. The use of cuttings often provides byproducts as a form of mineral extraction, commonly sand, clay or gravel; the cost of building drains, reinforcing banks against landslide and a high water table are factors which commonly limit its use in certain areas.
History
The term cutting appears in the 19th century literature to designate rock cuts developed to moderate grades of railway lines.[2] Railway Age's Comprehensive Railroad Dictionary defines a cut as "a passage cut for the roadway through an obstacle of rock or dirt".[3]
Types of cut
There are at least two types of cut, sidehill cut and through cut. The former permits passage of a transportation route alongside of, or around a hill, where the slope is transverse to the roadway or the railway. A sidehill cut can be formed by means of sidecasting, i.e., cutting on the high side balanced by moving the material to build up the low side to achieve a flat surface for the route. In contrast, through cuts, where the adjacent grade is higher on both sides of the route, require removal of material from the area since it cannot be dumped alongside the route.[4]
Lock cut
A lock cut is a section of a river or other inland waterway immediately upstream and downstream of a lock which has been modified to provide locations for boats to moor while waiting for the lock gates to open or to allow people to board or alight vessels.
A ledge
A ledge is a cut in the side of a cliff well above the bottom of a gorge
Notable cuts
Notable canal cuts
- Culebra Cut (Gaillard Cut) on the Panama Canal
- Dawesville Cut
- Corinth Canal
Notable railway cuts
- Olive Mount cutting, Liverpool
- Bergen Hill
- Duffy's Cut
- Talerddig cutting
- Windmill Hill Cutting
- Hellfire Pass
Notable roadway cuts
- Sideling Hill Cut on I-68
- Pikeville Cut-Through on U.S. Route 23 in Kentucky
See also
- Cut-and-cover
- Dashrath Manjhi
- Embankment (transportation)
- Flying arch, use of a dummy arch bridge to stabilise cutting walls against landslip (landslide)
- Trench
References
- ↑ Herbert L. Nichols, Jr., and David A. Day, P.E., Moving the Earth: The Workbook of Excavation, 5th ed. (New York: McGraw-Hill, 2005), pp. 8.16 et seq.
- ↑ Alexander Smith (1875) A new history of Aberdeenshire
- ↑ Robert G. Lewis et al., eds., Railway Age's Comprehensive Railroad Dictionary (Omaha, Neb.: Simmons-Boardman Books, 1984), p. 48. This reference does not include a definition for the corresponding term fill.
- ↑ Nichols and Day, Moving the Earth, p. 8.16.
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