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Related to trench: Mariana Trench


see oceanocean,
interconnected mass of saltwater covering 70.78% of the surface of the earth, often called the world ocean. It is subdivided into four (or five) major units that are separated from each other in most cases by the continental masses. See also oceanography.
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in mining, an open excavation in the ground. A trench has a trapezoidal cross section, and its length is many times greater than its width.

Sloping main, or primary, trenches are used in stripping an opencut mine or an individual area of such a mine, and also in establishing a haulage system to link the working levels with the surface. A horizontal, or cross-sectional, trench is designed to establish the initial working front at a bench. In the case of irregular mountain terrain, a trench may have an irregular cross section (hasty trench).

Main trenches are classified on various bases. In terms of their relationship to the contours of the pit, they may be external or internal. They may be of the individual type (providing haulage for a single level), the group type (serving several levels), or the general type (for all working levels in the pit). On the basis of the traffic flow, they are classified as single trenches, with two-way traffic, and paired trenches, with one-way traffic.

The width of a horizontal trench depends on the location of the haulage system and excavation equipment in the horizon being stripped. The depth of a horizontal trench corresponds to the height of the horizon to be stripped. The optimum depth of an inclined main external trench is 50–60 m.

In pits with soft rock, trenches are excavated using multibucket excavators, dragline excavators, or scrapers; single-bucket excavators (trenchers) are used in pits with hard rock. Ejection explosions may be used in digging a trench. If conditions permit, the stripped rock is placed on the surface on one or both sides of the trench; otherwise, it is moved by vehicles to spoil banks.

The rate of excavation of trenches depends largely on the time required for construction of the pit and, in sloped and steeply inclined deposits, also on the productivity of the pit.

Trenches are also used in construction, for the laying of pipelines and cables.



A narrow, straight, elongate, U-shaped valley between two mountain ranges.
A narrow stream-eroded canyon, gulley, or depression with steep sides.
A long, narrow, deep depression of the sea floor, with relatively steep sides. Also known as submarine trench.


2. A housing, 1.
References in periodicals archive ?
Now, in another part of the Pacific, some earth scientists think they are beginning to see the earliest stages in the birth of a subduction zone that will eventually form a trench to the north and west of New Guinea.
Highlights from the Golondrina targets include Trench #4 that returned grading of 30.
The Gonzales branch is our second expansion outside the state of Texas, and will be the sixth fully-staffed operation of National Trench Safety in the United States.
Wallace Specialty Equipment has introduced a new series of trench graders that fills and compacts trenches in a single pass.
The Fremont branch is our first expansion outside the state of Texas, and will be the fifth fully-staffed operation of National Trench Safety in the United States.
In areas where conventional excavation is impossible or not practical, we partner with underground utility contractors providing them with clean, open trench ready for pipe installation," says Webb
GoldQuest" or the "Company") (TSX VENTURE:GQC)(FWB:M1W) is pleased to announce further high grade gold mineralization in new trench sampling on its' 100% owned Las Tres Palmas project in the western Dominican Republic.
The Minus-One Trench Shield reduces trench width by six inches.
was not responsible for a trench accident that injured a subcontractor's employee, John Bieruta of DuPage Topsoil.
SOQUEM"), collected this material from Trench 184 and Trench 221, two of four trenches excavated along the Lynx system in 2005.
Each trench is 165 feet long, 15 feet wide and of an unknown depth - topped by at least 3 feet of dirt.
A pre-fabricated, Slide Rail & Shore-Trak Cross Trench Utility Shielding System is available from Efficiency-Production, Inc.