Vertical stress redistribution around a retreating longwall face end

Book · Wed Nov 01 04:00:00 EST 1995

OSTI ID:124694

Payne, D A ^[1]; DeMarco, M ^[2]

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1. CANMET, Sydney, Nova Scotia (Canada). Cape Breton Coal Research Lab.
2. Bureau of Mines, Denver, CO (United States). Denver Research Center

Large excavations, such as longwall panels, result in extensive vertical stress redistribution in the surrounding strata. The large abutment stresses developed may produce damage to pre-existing or planned excavations in the same seam or in seams above and below the workings. Knowledge of the magnitude and location of these stress is therefore important in the design of mine openings; pillar sizes for panel and pillar layouts, roof supports in longwall gateroads and workings over or above pre-existing or planned extracting in adjacent seams. In an attempt to reduce costs, the Cape Breton Development Corporation (CBDC), a Federal Crown Corporation responsible for operating two retreat longwall coal mines, examined the potential for either interpanel barrier pillar width reduction or entire pillar elimination by the adoption of dual life gateroads for the longwall panels. In order to assess the potential for reduced interpanel barrier widths or total elimination, an investigation of the redistribution of vertical stresses around longwall panels in the Sydney Coalfield was established. The study was conducted jointly by the Cape Breton Coal Research Laboratory (CBCRL), of CANMET (a division of Natural Resources Canada) and the Denver Research Center (DRC) of the United States Bureau of Mines. The program included monitoring of vertical stress changes around longwall panels and gateroad behavior in two seams. USBM-style hydraulic borehole pressure cells connected to chart recorders for continuous monitoring were deployed at four sites, two at Lingan Colliery and two at Phalen Colliery. This report describes the investigations conducted at Phalen Colliery. Contoured plots of stress redistribution around two sites are presented.

• OSTI ID: 124694
• Report Number(s): CONF-950811--; ISBN 0-930284-56-9
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL MINING
DESIGN
EXPERIMENTAL DATA
LONGWALL MINING
MEASURING METHODS
MINE ROADWAYS
NOVA SCOTIA
RETREAT MINING
STRATA CONTROL
STRATA MOVEMENT
STRESS ANALYSIS
STRESS RELAXATION
SUPPORT PILLARS
WORKING FACES