Longwall gate road stability in a steeply pitching thick coal seam with a weak roof.
Barron LR; DeMarco MJ
Denver, CO: U.S. Department of the Interior, Bureau of Mines, RI 9580, 1995 Jan; :1-36
The U.S. Bureau of Mines conducted a ground pressure analysis of a wide abutment-type chain pillar in a two-entry gate road of a Western U.S. coal mine with an extremely weak immediate roof. This report discusses gate road layout and performance and secondary support effectiveness. The results of the pillar pressure study are compared to pillar loading predicted by a widely used pillar design method and to similar studies in other mines. A stability evaluation of the most recent longwall headgate, using the USBM Analysis of Longwall Pillar Stability (ALPS) indicates marginal stability in first-panel mining and instability in second-panel mining. ALPS and the USBM Coal Mine Roof Rating (CMRR) system are used to evaluate tailgate-mining stability of the previous gate roads and to determine pillar and entry width and top coal thickness criteria for tailgate stability in future panels.
Coal-mines; Coal-seams; Rock-mechanics; Mechanical-properties; Strata-control; Overburden; Structural-design; Structural-analysis; Underground-mining; Mining-engineering; Longwall-mining; Roofs; Stability-analysis; Mine-roadways
Report of Investigations
NTIS Accession No.
Denver, CO: U.S. Department of the Interior, Bureau of Mines, RI 9580