Investigation of the Failure of Roofs in Coal Mines.
NTIS: PB/243-375 Available for Reference At Bureau Libraries :135 pages
This report provides the results of studies concerning several environmental features suspected of altering the strength characteristics of shale in mine roof rock and discusses several methods of laboratory testing sample roof rock to determine whether or not it is prone to failure. Among the features examined affecting strength characteristics are humidity, temperature, and recrystallization of minerals in the shale. The results of several tests concerning these features are given.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB/243-375 Available for Reference At Bureau Libraries
University of Missouri-Rolla