Excavation(redirected from excavation of optic disk)
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Related to excavation of optic disk: Optic disc pit
the process of removing rock or earth from a solid, broken, or unconsolidated layer by means of an excavator, bulldozer, scraper, or similar machine. In earthwork practice, the term “excavation” may also include the entire work cycle, that is, digging, transportation, and dumping of the earth with excavators.
Soft, loose, and dense rock is usually excavated directly from the solid formation by successive removal of layers of ground; rock that has been broken up beforehand is excavated from piles or loosened layers. Three types of excavation are distinguished according to the mutual position of the face and the horizon on which the machine is working: the face may be above or below the machine horizon, or a combination of the two arrangements may be used. Because digging is the principal component of the process of excavation, it is conventional to describe the process with respect to the specific resistance to digging. This quantity is affected by the physicomechanical properties of the rock or earth, the type of excavating machine used, the design and dimensions of the working member, and the procedure followed in working the face.
REFERENCESDombrovskii, N. G. Ekskavatory. Moscow, 1969.
Rzhevskii, V. V. Protsessy otkrytykh gornykh rabot, 2nd ed. Moscow, 1974.
Beliakov, Iu. I., and V. M. Vladimirov. Sovershenstvovanie ekskavatornykh rabot na kar’erakh. Moscow, 1974.
IU. D. BUIANOV