Seismic tomographic investigation of floor strata beneath a coal pillar in an underground coal mine
- Southern Illinois Univ., Carbondale, IL (United States)
In partial extraction room-and-pillar mining systems, a pillar may punch into a soft floor and cause floor heave and buckle if the immediate floor layer is thin and relatively weak. This is caused by the pillar creating a stress field that exceeds the bearing capacity of the floor rock. Failures of floors and entries may in turn result in roof and coal pillar failures and in surface and subsurface movements. The ultimate bearing capacity of floor strata is extremely sensitive to the thickness of weak floor strata, and the stress distribution within and beneath the pillar is directly affected by the geological structure and lithology that underlies the pillar. It is the purpose of this research to study the geological structure of floor strata underneath a coal pillar as well as the stress distribution within and beneath the pillar through interpretation of velocity tomograms obtained by seismic refraction tomography supplemented and constrained by data from standard seismic refraction techniques and geological field observations. The tomography experiment presented here is apparently the first application of round-the-pillar geophysical tomography in an underground coal mine.
- OSTI ID:
- 106358
- Report Number(s):
- CONF-9210116--; ISBN 1-885189-02-8
- Country of Publication:
- United States
- Language:
- English
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