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Investigations of differential strata movements and water table fluctuations during longwall operations at the Somerset Mine No. 60.

Authors
Barla GB; Bashkov S
Source
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, Contract - G-9041, 1978 Jan; :1-149
Link
NIOSHTIC No.
10003678
Abstract
This research work was directed toward the acquisition of data describing the phenomenology of failure of superincumbent strata during longwall mining operations in the Pittsburgh coal seam. The specific site for the study was the second panel in the Somerset Mine No. 60, belonging to the Bethlehem Steel Company, and located near Washington, Pennsylvania. The thickness of the coal approximated 68 inches. Two boreholes were instrumented as strata movement monitoring stations, drilled from the surface to the coal seam, which was located under 330 feet to 430 feet of cover. Five additional holes were drilled to an approximate depth of 150 feet in order to permit observations on the water table fluctuations. Cores recovered from the two instrumented boreholes were geomechanically logged throughout. The recorded data indicate that strata behavior differs in locations close to the first break from those which follow the establishment of regular caving. The fracture of impermeable layers inevitably leads to sudden drops in the water table. The data suggest the existence of a very steep angle of fracture growth coupled to an immediate propagation upward for the caved area.
Keywords
Longwall mining; Strata movement; Coal mining; Experimental data; Extensometers; Geology; Ground subsidence; Ground water; Level indicators; Monitoring; Tables; Underground mining
Publication Date
19780101
Document Type
CP; Final Contract Report
Fiscal Year
1978
NTIS Accession No.
FE90411
NTIS Price
A08
Identifying No.
Contract - G-9041
NIOSH Division
PRC
Source Name
Pittsburgh, PA: U.S. Department of the Interior, Bureau of Mines, Contract - G-9041
State
PA; NY; TN
Performing Organization
Columbia University, New York
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division