Evaluating bump control techniques through convergence monitoring
A coal mine bump is the violent failure of a pillar or pillars due to overstress. Retreat coal mining concentrates stresses on the pillars directly outby gob areas, and the situation becomes critical when mining a coalbed encased in rigid associated strata. Bump control techniques employed by the Olga Mine, McDowell County, WV, were evaluated through convergence monitoring in a Bureau of Mines study. Olga uses a novel pillar splitting mining method to extract 55-ft by 70-ft chain pillars, under 1,100 to 1,550 ft of overburden. Three rows of pillars are mined simultaneously to soften the pillar line and reduce strain energy storage capacity. Localized stress reduction (destressing) techniques, auger drilling and shot firing, induced approximately 0.1 in. of roof-to-floor convergence in ''high'' -stress pillars near the gob line. Auger drilling of a ''low''-stress pillar located between two barrier pillars produced no convergence effects.
- Research Organization:
- Bureau of Mines, Dept. of the Interior, Pittsburgh, PA
- OSTI ID:
- 6206905
- Journal Information:
- Coal Min. Process.; (United States), Journal Name: Coal Min. Process.; (United States) Vol. 24:7; ISSN CMPRB
- Country of Publication:
- United States
- Language:
- English
Similar Records
Performance of a novel bump-control pillar-extracting technique during room-and-pillar retreat coal mining. Report of Investigations/1989
Room-and-pillar mining in bump-prone conditions and thin pillar mining as a bump mitigation technique. Report of Investigations/1993
Related Subjects
012031* -- Coal
Lignite
& Peat-- Underground Mining-- Strata Mechanics & Control-- (1987-)
AUGER MINING
COAL MINES
FAILURES
MINES
MINING
MONITORING
NATIONAL ORGANIZATIONS
OVERBURDEN
RELAXATION
RETREAT MINING
STRAINS
STRATA CONTROL
STRESS RELAXATION
STRESSES
SUPPORT PILLARS
UNDERGROUND FACILITIES
UNDERGROUND MINING
US BUREAU OF MINES
US DOI
US ORGANIZATIONS