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U.S. Department of Energy
Office of Scientific and Technical Information

Geologic and ground-control aspects of an experimental shortwall operation in the Upper Ohio Valley. Report of investigations

Technical Report ·
OSTI ID:7331507
Valley Camp No. 3 Mine was the scene of an experimental shortwall introduced in 1973 in an attempt to improve the recovery from the Pittsburgh coalbed in the Ohio Valley where adverse ground conditions have imposed partial extraction methods with only 40-55 pct recovery. The Bureau of Mines, monitored ground pressures and caving in the shortwall section in an effort to determine whether the roof strata, notably the limestone main roof, will cave to the extent that roof pressures at the face are relieved and whether the powered roof supports can sustain the roof load. The Bureau's approach included mapping of clay veins, instrumentation of chain pillars and shortwall panels with encapsulated pressure cells, recording hydraulic pressures in the shortwall chocks and core drilling underground and from the surface. The experimental shortwall was a qualified success. Recovery gained 5.4 pct compared with partial extraction. Apparently, the limestone strata caved, and the roof pressure was relieved. (GRA)
Research Organization:
Bureau of Mines, Pittsburgh, Pa. (USA). Pittsburgh Mining and Safety Research Center
OSTI ID:
7331507
Report Number(s):
PB-251983; BM-RI-8112
Country of Publication:
United States
Language:
English