Regional horizontal stress and its effect on longwall mining in the northern Appalachian coal field

Book · Wed Nov 01 04:00:00 UTC 1995

OSTI ID:124668

Su, D W.H.; Hasenfus, G J ^[1]

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1. CONSOL, Inc., Library, PA (United States)

This paper presents the results of in situ horizontal stress measurements using a Minifrac system in several northern Appalachian coal mines. The effect of stress magnitude and orientation on longwall gate entry stability was analyzed using a series of three-dimensional finite element analyses. The best headgate stability is achieved if the maximum horizontal stress is aligned with the direction of longwall retreat or if the panel is oriented such that the maximum stress relaxes over the headgate due to the presence of the newly formed gob. The degree of horizontal stress damage to longwall gate entries depends largely on the stress magnitude and roof geology. Accurate assessments of support or design techniques which may mitigate longwall headgate or tailgate instability in areas of thinly laminated roof and high horizontal stresses must account for the in situ horizontal stress state and site specific roof geology. The ability to measure stresses and map geology is thus essential to prevent ground control failures at the longwall headgate.

• OSTI ID: 124668
• Report Number(s): CONF-950811--; ISBN 0-930284-56-9
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
APPALACHIAN MOUNTAINS
COAL MINING
COAL SEAMS
DEFORMATION
EXPERIMENTAL DATA
HYDRAULIC FRACTURING
LONGWALL MINING
MINE ROADWAYS
OHIO
ORIENTATION
PENNSYLVANIA
STRATA CONTROL
STRESS ANALYSIS
STRESS RELAXATION
STRESSES
WEST VIRGINIA