Boring (earth)
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Boring is
- return samples of the soil and/or rock through which the drill passes
- access rocks from which material can be extracted
- access rocks which can then be measured
- provide access to rock for purposes of providing engineering support
Unlike drilling in other materials where the aim is to create a hole for some purpose, often the case of drilling or coring is to get an understanding of the ground/lithology. This may be done for prospecting to identify and quantify an ore body for mining, or to determining the type of foundations needed for a building or raised structure, or for underground structures, including tunnels and deep basements where an understanding of the ground is vital to determining how to excavate and the support philosophy. Drilling is also used in vertical and inclined shaft construction.
History
Borehole drilling has a long history. Han dynasty China (202 BC – 220 AD) used deep borehole drilling for mining and other projects. Chinese borehole sites could reach as deep as 600 m (2,000 ft).[1]
Methods
When drilling in stone, one must pay particular attention to the type of material. There are three different classifications of drill bits used for drilling into stone: soft, medium, and hard. Soft formation rock bits are used in unconsolidated sands, clays, and soft limestones, etc. Medium formation bits are used in
Soft ground drilling can be undertaken using a
Testing of the material in
Superdeep Borehole
In 1961 the United States began
The
Further attempts are planned by American consortia and further Russian attempts in Finland.
Ice boring
See also
- Directional boring
- Drifter (drill)
- Oil well
- Standard penetration test
- Tunnel boring machine
References
- ^ * Loewe, Michael. (1968). Everyday Life in Early Imperial China during the Han Period 202 BC–AD 220. London: B.T. Batsford Ltd.; New York: G.P. Putnam's Sons, p. 194.