Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Sizing of final stumps for safer pillar extraction.

Authors
Mark-C; Zelanko-JC
Source
Proceedings of the 20th International Conference on Ground Control in Mining, August 7-9, 2001, Morgantown, West Virginia. Peng SS, Mark C, Khair AW, eds., Morgantown, WV: West Virginia University, 2001 Aug; :59-66
Link
NIOSHTIC No.
20021383
Abstract
Pillar recovery continues to be one of the more hazardous activities in underground coal mining. Safety requires that the roof above the intersection remain stable until after the pillar has been extracted. Artificial supports (timbers and Mobile Roof Supports) are essential to roof stability, but so is the final remnant stump or pushout. Traditional mining practices usually called for the complete extraction of the final stump, but the recent trend (both in the U.S. and internationally) seems to be towards mining plans that leave a remnant stump. For this study, a sample of roof control plans from the Mine Health and Safety Administration (MSHA) Coal Districts were analyzed to determine current pillar recovery practices. Both full- and partial-extraction plans were included. Special attention was paid to whether plans require that a final sump be left, and whether requirements regarding the dimensions of the remnant sump are included. Foreign experience with final stumps is also summarized. It seems that the risk of major pillar falls can often be reduced by leaving final stumps that are large enough to protect the intersection, but small enough that they do not inhibit the caving of the gob. Because final stumps are often irregular in shape, a new approach for estimating their strength is described. Analyses were conducted to assess the effect of seam height and depth of cover on the potential variation in the size of remnant stumps.
Keywords
Mining-industry; Coal-mining; Underground-mining; Rock-mechanics; Rock-falls; Safety-practices; Safety-measures; Geology; Room-and-pillar-mining
Contact
NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
Publication Date
20010807
Document Type
Conference/Symposia Proceedings
Editors
Peng-SS; Mark-C; Khair-AW
Fiscal Year
2001
NTIS Accession No.
NTIS Price
ISBN No.
0939084569
NIOSH Division
PRL
Source Name
Proceedings of the 20th International Conference on Ground Control in Mining, August 7-9, 2001, Morgantown, West Virginia
State
WV; PA
TOP