Clay veins: Their occurrence, characteristics, and support
These detrimental aspects have prompted the Bureau of Mines to investigate the physical characteristics of and roof instability problems associated with clay veins. The investigators found that clay veins normally occur in more stable, less rapidly subsiding coal basins. Clay veins result when tensile stresses develop fissures that are later infilled. These fissures can be propagated by compactional processes and/or tectonic stresses during and subsequent to coalification. The Bureau also found that associated faults, fractures, and slickenside planes commonly parallel clay veins and disrupt the lateral continuity of the immediate and, sometimes, main roof. When clay veins parallel or subparallel the direction of face advance, the roof is segmented into cantilever beams, causing unstable conditions. Consequently, the strate on either side of the clay veins should be bolted and strapped together to form a beam.
- OSTI ID:
- 6965472
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
CLAYS
PHYSICAL PROPERTIES
COAL SEAMS
ROOFS
CRACK PROPAGATION
ROCK MECHANICS
COALIFICATION
GEOLOGIC FISSURES
TECTONICS
US BUREAU OF MINES
COAL DEPOSITS
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MECHANICS
MINERAL RESOURCES
NATIONAL ORGANIZATIONS
RESOURCES
US DOI
US ORGANIZATIONS
012010* - Coal
Lignite
& Peat- Mining- Planning & Surveying- (1987-)
580300 - Mineralogy
Petrology
& Rock Mechanics- (-1989)