a. Small faults. BS, 11
b. A tool used at the mouth of a borehole to grip the drill rods or the
casing, as these are being inserted or withdrawn. BS, 9
c. See:backs; slickensides.
A tool for extracting tubing from a borehole.
The surface along which an earth bank is liable to fail under load.
Hammond
In a bank of homogeneous earth or clay, the slip surface of failure
closely follows the arc of a circle that usually intersects the toe of the
bank. Stability depends upon fixing the position of the center of rotation
of the slip surface along which the greatest shearing resistance would be
required for equilibrium. See also:circular slip; landslide.
Nelson
A sensor installed on a conveyor drive pulley snub roller, on a return
roller, on a bend roller, or on a head pulley that will detect a slowing
of the conveyor, resulting in conveyor shut-down to avoid conveyor belt
fires or overloading of the conveyor because of the slipping.
A device used like a core spring, consisting of a series of tapered wedges
contained in slotted recesses in a circular ring or sleeve; as the core
enters the inner tube, it lifts the wedges along the taper, and when the
barrel is lifted, the wedges are pulled tight against the core.
Long
A mineral vein accompanied by faulting or dislocation.
The rate, expressed in feet (meters) per minute, at which a given size and
shape of rock particle will descend or settle in water; e.g., the slip
velocity in water of a round, flat particle of rock, 1/2 in (1.27 cm) in
diameter, is about 54 ft/min (16.5 m/min). Long
A solid-tube sampler with a slight twist on the bottom and an offset slit
in the side. When rotated, the lip of the slit scrapes a sample from the
side of a borehole. Long
Eng. A pick. Fay
Circular saw used in preparing rock specimens. The cutting edge
incorporates diamond dust, and the thin steel disk revolves at high speed.
Pryor, 3
A shot put into a large mass of coal detached by a previous blast.
Eng. A piece of rich ore used to tempt persons into a mining enterprise.
See also:salting a mine
a. The entry, passage, or main working gallery of a coal seam that dips at
an angle. See also:incline
b. Inside slope.
c. See gradient.
d. An inclined passage driven from the dip of a coal vein. CF:slant
When not open at one end to the surface, it is known as an inside slope.
See also:incline; plane.
e. The inclination of a mine roadway or coal seam. Nelson
f. The main working gallery or entry of a coal seam that dips at an angle
and along which mine cars are hauled. Nelson
g. An entrance to a mine driven down through an inclined coal seam; also,
a mine having such an entrance. An inside slope is a passage in the mine
driven through the seam by which coal is brought up from a lower level.
Korson
h. In a mining statute or in mining parlance, an inclined way, passage, or
opening used for the same purpose as a shaft. Sometimes used to embrace
the main haulage passageway, whether inclined or level. Ricketts
i. The degree of inclination to the horizontal. Usually expressed as a
ratio, such as 1:25, indicating one unit rise in 25 units of horizontal
distance; or in a decimal fraction (0.04); degrees (2 degrees 18'); or
percent (4%). It is sometimes expressed as steep, moderate, gentle, mild,
flat, etc. Also called gradient. Hunt
j. In surface mining, the steepest possible slope of an excavation that is
consistent with safety of working. Mining
k. An inclined passageway (tunnel) from the surface, through the strata,
that intersects the coal bed to be developed.
A passageway parallel to the haulage slope used for the passage of the air
current.
A truck on which the cars are raised at slopes or steep dips. Also called
slope carriage. See also:carriage
a. Usually a troughed belt conveyor used for transporting coal or ore
through an inclined passage to the surface from an underground mine.
See also:apron conveyor; belt conveyor; flight conveyor.
b. Generally less than 1,000 ft (304.8 m) in length, the conveyor is
designed to raise or lower material on steep grades and is commonly used
to transport material from discharge bins or a main haulage conveyor to
the outside. It is often used as a transfer conveyor from a lower to a
higher entry or to a gangway in a pitching seam. NEMA, 2
A calculation of deduction from a length as measured on a slope to bring
it to its true horizontal length. See also:tape corrections
In anthracite and bituminous coal mining, one who operates a hoisting
engine to haul loaded and empty mine cars along a level or inclined
haulage road (slope or plane) in a mine on a level, or from a lower to an
upper level, or to the mine surface. Also called drag engineer; dragline
engineer; drumman; plane engineer; plane tender; slope tender. DOT
a. The downward and outward movement of rock or unconsolidated material as
a unit or as a series of units. Also called slump. Leet, 1
b. Failure of the mass of soil beneath a natural slope or a slope of an
embankment by the formation of a slide. Huntington
c. Slope failure may take place by one or more of three processes: (1)
raveling, in which the material will assume an angle of repose approx.
equal to the angle of friction of the material, and within limits the
stable slope is independent of the weight of the mass, the height of the
slope, and the size of the fragments. It is, however, characteristic of
each rock material and is dependent on angularity, grading, and mineral
content; (2) transitional failure, in which failure occurs mostly along
existing fault planes or other planes of weakness. Stability is a function
of rock cohesion, the angle of internal friction, the angle of dip of the
slip plane, the length of the slip surface, and the total weight of the
block; and (3) rotational or base failure, which is uncommon in open-pit
mines or rock cuts because of geologic structure. However, in the case of
homogeneous cohesive material--very deep excavation or low rock
strength--failure may occur along a cylindrical surface. Four types of
slope failure are rockfall, rock flow, plane shear, and rotational shear.
See also:rockfall; rock flow; plane shear; rotational shear.
Syn:base failure
d. Gradual or rapid downslope movement of soil or rock under gravitational
stress, often as a result of man-caused factors; e.g., removal of material
from the base of a slope. AGI
A staff gage placed on an incline and graduated to indicate vertical
heights. Seelye, 1