Experimental investigation of room and pillar coal mining in the eastern United States. [6 refs]

Conference · Fri Oct 01 04:00:00 EDT 1976

OSTI ID:7212338

Langland, R T

A joint experimental-analytical program was undertaken to determine the fundamental underground behavior during room and pillar mining of coal. A coal mine in Eastern Ohio was selected for the experiment. The coal seam was approximately 91 m underground and was located in a region of rolling hills. Seam thickness varied from 1.2 to 1.8 m. Mining was done with drill and blast techniques instead of using a continuous miner. Three test sites were instrumented; two sites with good roofs and one with a weak roof. For the two sites with good roof, one intersection in a development area, and two intersections in a production area were instrumented. One intersection in the third site with poor roof conditions was instrumented. Three kinds of measurements were made in each intersection; roof bolt loads, differential displacement of roof strata (sag), and roof-to-floor convergence. This instrumentation was placed as the working face advanced. A three-dimensional finite element study of the instrumented areas was conducted. Excellent agreement with the field data was obtained. The analysis included excavation effects. A clearer understanding of the load transfer and ground movement phenomena was obtained from the studies. Roof bolt loads and sag showed excellent correlation with excavation and exhibited no time dependent effects. Roof-to-floor convergence exhibited time dependence and the fastest convergence rate occurred immediately after excavation and became constant after several weeks. Changes in roof bolt loads during excavation were strongly influenced by movement of the anchor point.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7212338
• Report Number(s): UCRL-78758; CONF-770422-1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
COAL DEPOSITS
COAL MINING
DATA ACQUISITION SYSTEMS
DEPTH
DIMENSIONS
ENERGY SOURCES
EQUIPMENT
EXCAVATION
GEOLOGIC DEPOSITS
MINING
MINING EQUIPMENT
NORTH AMERICA
PRODUCTIVITY
RESOURCES
ROOF BOLTS
ROOFS
ROOM AND PILLAR MINING
THICKNESS
UNDERGROUND MINING
USA