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Geologic and Ground Control Aspects of an Experimental Shortwall Operation in the Upper Ohio Valley.

Moebs-NN; Curth-EA
NTIS: PB 251 983 :30 pages
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 area where adverse ground conditions have imposed partial extraction methods with only 40 to 55 percent recovery of the valuable resource. The Bureau of Mines, under a cooperative agreement with Valley Camp Coal Company, 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 efforts included mapping of clay veins, instrumentation of chain pillars and shortwall panels with encapsulated pressure cells, recording hydraulic pressures in the legs of the shortwall chocks, and core drilling underground and from the surface. The experimental shortwall was a qualified success. Recovery increased 5.4 percent compared with partial extraction. Pressures in chain pillars and the abutment zone were not excessive. Hydraulic pressures in the chock legs did not approach the yielding pressure. Apparently, the limestone strata caved and the roof pressure at the face was relieved.
Publication Date
Document Type
IH; Report of Investigations
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
RI 8112
NIOSH Division
Source Name
NTIS: PB 251 983
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division