Effects of soft-floor interaction on room-and-pillar mining

Journal Article · Tue Jul 01 04:00:00 EDT 1986 · Miner. Matters; (United States)

OSTI ID:5730851

Chandrashekhar, K

Ground control in sedimentary rocks involves close interaction among the roof, pillar, and floor. Limited studies have been done to examine the effects of floor interaction on the stability of room-and-pillar mining. This study, therefore, was designed to meet the following objectives: (1) review techniques for coal pillar design with soft floor; (2) characterize properties of underclays in relation to pillar punching and, hence, mine subsidence; and (3) develop a predictive technique to estimate pillar punching and its time-dependent effects. The research program involves library, laboratory, and field geotechnical studies. The analytical part will chiefly consist of finite element modeling. The research sites will be two Midwest coal mines which are currently experiencing problems associated with soft floor. An extensive review of currently used pillar design techniques has been completed. Data on laboratory and field strength characteristics have been compiled and reviewed. All available data on the geology and stratigraphy of the area, including strength properties of roof and floor rock, were assessed. Presently, the analysis of all the data collected is underway - a step in the direction of building the finite element model. A two-dimensional model of the existing mine geometry is also in progress. This model will be analyzed for elastic, elastic-plastic, and elastic-plastic-time-dependent behavior. Later, a three-dimensional model of the instrumented site will be made. Field observations of loads, convergence, and sag will be used for model validation in both cases. This model, with suitable modifications, will then be verified for predictability using another mine.

• Research Organization: Southern Illinois Univ., Carbondale
• OSTI ID: 5730851
• Journal Information: Miner. Matters; (United States), Journal Name: Miner. Matters; (United States) Vol. 8:4; ISSN MIMAE
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012031* -- Coal
Lignite
& Peat-- Underground Mining-- Strata Mechanics & Control-- (1987-)
COAL MINING
DESIGN
ELASTICITY
FINITE ELEMENT METHOD
FLOORS
FORECASTING
GEOLOGY
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MINING
NUMERICAL SOLUTION
PLASTICITY
RESEARCH PROGRAMS
ROOFS
ROOM AND PILLAR MINING
STRATA CONTROL
STRATA MOVEMENT
STRATIGRAPHY
TENSILE PROPERTIES
TIME DEPENDENCE
UNDERGROUND MINING