Open-cut

In civil engineering, a cut or cutting is where soil or rock material from a hill or mountain is cut out to make way for a canal, road or railway line.

In cut and fill construction it keeps the route straight and/or flat, where the comparative cost or practicality of alternate solutions (such as diversion) is prohibitive. Contrary to the general meaning of cutting, a cutting in construction is mechanically excavated or blasted out with explosives. Some cuts are make on one side of a slope or a cliff, others directly through the middle or top of a hill. Generally, a cut is open at the top (otherwise it is a tunnel). A cut is (in a sense) the opposite of an embankment.

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. 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 term cutting appears in the 19th century literature to designate rock cuts developed to moderate grades of railway lines.Railway Age's Comprehensive Railroad Dictionary defines a cut as "a passage cut for the roadway through an obstacle of rock or dirt".

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.

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