Details:

Personal Author:
Barczak, Thomas M.
Corporate Authors:
United States. Bureau of Mines.
Description:
"This U.S. Bureau of Mines study evaluates factors that influence longwall support and strata interaction. The longwall system is composed of an immediate and main roof structure and three supporting foundations: longwall panel, powered roof supports, and gob waste. The main roof forms a structure that is generally supported by all three foundations, while the immediate roof acts as a beam that cantilevers from the coal face to the powered support. In most cases, shield loading involves a complex interaction of both main roof and immediate roof behavior and is a combination of loads produced from convergence of the main roof and displacements of the immediate roof caused by deformations of the cantilevered roof beam. Since the shield stiffness remains constant for all leg pressures and main roof convergence is irresistible in terms of shield capacity, the shield must be able to control the behavior of the immediate roof or floor structure for shield loading to be sensitive to setting pressures. If the goal is to minimize total shield loading, any active setting force must be offset by reduced passive shield loading to justify the active setting loads. Field data suggest that the typical reductions in passive loading do not justify the required increases in setting pressure in some applications." - NIOSHTIC-2

NIOSH no. 10011078


Subject:
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Longwall Mining -- Mathematical Models.
Mine Roof Control -- Mathematical Models.
Rock Mechanics -- Mathematical Models.

Series:
Report of investigations (United States. Bureau of Mines) ; 9394
Document Type:
Report
Collection(s):
National Institute for Occupational Safety and Health
Main Document Checksum:
[+]
urn:sha256:46308f269fa8cfbccce5ea6e346379fb7dfc6505f430d4c99eaf09638ca2288d
File Type:

Supporting Files

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