Study of coal mine roof behavior during mining. [6 refs]

Conference · Mon Jan 10 04:00:00 EST 1977

OSTI ID:7099835

Langland, R T; Owens, J K; Dixon, J D

The U.S. Bureau of Mines has conducted underground tests and computer analyses to study coal mine roof behavior. Southern Ohio Coal Company provided test sites in their Meigs mines located near Albany, Ohio. Testing apparatus was adapted for monitoring roof behavior at the face of mining from a remote surface location. Finite element analyses were applied to study the structural conditions present. Test sites were located at three different intersections of entries and crosscuts of the room-and-pillar mine. Electrical read-out instruments were used to record roof bolt loads, roof sag, and roof-floor convergence. They were installed during the roof bolting cycle of a conventional mining section and data was recorded for several months. Normal mining operations continued throughout the test period with minimal interruptions due to the installation and monitoring of the instruments. A computerized data acquisition system, partly underground, partly on surface, permitted continuous monitoring of data and its retrieval, display, manipulation, and storage. The finite element code used to model the test sites accounted for three-dimensional geometry, nonlinear material behavior, and the mining excavation and bolt installation sequences. Results of the test are highly variable. Comparable values between test and analysis results were obtained by applying statistical averaging of roof test data. Results of the analyses indicate that bolts have a lesser effect on the gross behavior of mine roofs than has been indicated and that bolt load changes are strongly influenced by mining excavation sequence, bolt-placement sequence, and face distance.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7099835
• Report Number(s): UCRL-79145; CONF-770312-2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
016000 -- Coal
Lignite
& Peat-- Health & Safety
COAL MINES
DATA ACQUISITION SYSTEMS
EQUIPMENT
MINES
MINING
MINING EQUIPMENT
MONITORING
NATIONAL ORGANIZATIONS
PERFORMANCE TESTING
RESEARCH PROGRAMS
ROOF BOLTS
ROOFS
TESTING
UNDERGROUND MINING
US BUREAU OF MINES
US ORGANIZATIONS