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Development of a Roof Competence Tester.

Authors
Czirr-JB
Source
NTIS: PB/86-135415 :63 pages
Link
NIOSHTIC No.
10004884
Abstract
A 4-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 this 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.
Publication Date
19850101
Document Type
CP; Final Contract Report;
Fiscal Year
1985
NTIS Accession No.
PB86-135415
NTIS Price
A05
Identifying No.
OFR 114-85
NIOSH Division
PRC;
Source Name
NTIS: PB/86-135415
Performing Organization
Minority Enter.ser.assoc.
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