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Roof and floor of coal seam
Release time:
2022-11-23
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Roof and floor of coal seam
Coal seams are layered solid combustible minerals formed by the accumulation of a large number of plant remains and the formation of coal. LocatedThe rock layer within a certain distance of the upper part of the coal seam is called the coal seam roof. The name of the rock layer located within a distance below the coal seam.for the coal seam floor.
1. Coal seam roof
Coal seam roof can also be divided:
(1) False top. The extremely unstable rock layer located above the coal seam is generally 0.5m thick.Under, very easy to collapse, usually with the take. Pseudo-roof only exists on some coal seams, not all coal seamsThere is. The fake top is only harmful, not beneficial, and is a potential safety hazard.
(2) Direct top. A rock layer located on a coal seam or pseudo-roof with a certain degree of stability.
(3) Basic top. Also known as the old roof, located on the direct roof or coal seam, the strength of the larger, difficult to collapse.
2. Coal seam floor
The seam floor is also divided:
(1) Direct bottom. A low strength rock layer located beneath a coal seam.
(2) Basic bottom. Also known as the old bottom, located in the direct bottom or under the coal seam, relatively hard rock formation.
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