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Comprehensive ground control study of a mechanized longwall operation. Volume I. Final report

Technical Report ·
OSTI ID:7301739
The prime objective of the study was to make strata control measurements on an operating longwall, from which engineering design values for structural parameters such as convergence in the face area and support load density, as function of the rate of mining and the strata properties can be extracted. Instruments installed in the mine were borehole pressure cells, convergence recorders, horizontal roof strain indicaters, differential floor movement systems, and lateral roof and floor movement systems. Instruments installed on the surface, above the instrumented longwall panels consisted of slope indicator system, vertical bed settlement probe system, and shear displacement detecting system. A comprehensive surface subsidence study was conducted in conjunction with the instrumentation. In addition to the instrumentation and monitoring, special tests were conducted to determine the bearing capacity of the roof and floor rocks, in situ modulus of coal, roof and floor rocks, and response of borehole pressure cells to ground stress. Cores of coal measure rocks were collected for the physical property tests. Face observations were made to detect various roof behavior parameters under the different jack setting pressures. This report essentially describes the instrumentation work, special tests, and presents the data collected.
Research Organization:
Harza Engineering Co., Chicago, IL (USA)
OSTI ID:
7301739
Report Number(s):
PB-262475
Country of Publication:
United States
Language:
English