Development of a roof competence tester. Report for 18 August 1980-19 March 1985
A four-year program was completed to develop a technique for measuring roof competence in underground coal mines. The preferred technique employs a tracer gas that is injected into a roof borehole drilled near the working face. The tracer gas performs the dual purpose of determining the pressure loss rate from the borehole and of marking the diffusion pattern of the escaping gas. The primary detection technique relies upon observation of the rate of pressure drop in a hole drilled in the roof strata under test. If the measurement indicates a significant probability of roof collapse, the gas diffusion pattern is outlined with the Leakgun tracer-gas detector. These two techniques provide a comprehensive method for predicting the relative probability of roof collapse in operating coal mines.
- Research Organization:
- MESA Corp., Salt Lake City, UT (USA)
- OSTI ID:
- 6170690
- Report Number(s):
- PB-86-135415/XAB
- Country of Publication:
- United States
- Language:
- English
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