Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Effects of Ancient Stream Channel Deposits on Mine Roof Stability: a Case Study.

Authors
Ingram-DK; Chase-FE
Source
USBM, :1-33
Link
NIOSHTIC No.
10005982
Abstract
The Bureau of Mines conducted underground mapping and rock strength tests to describe and analyze mine roof conditions surrounding ancient stream channel deposits (paleochannels) in the Pittsburgh coalbed in southwestern Pennsylvania. Paleochannels in the study mine consist of sandstone and/or siltstone and affect the Pittsburgh coalbed through erosion and/or differential compaction. Differentially compacted sediments within and adjacent to channel deposits caused slip planes, faults, clay-dike faults, clastic dikes (clay veins), coalbed rolls, and slumped structures. Paleochannels can be predicted by recognizing these features and associated sediments, which allows for modification of long- and short-term mine planning and development. Mine entries located beneath the paleochannel deposits exhibit less stable roof conditions than entries with normal (nonchannel) roof. Paleochannel deposits comprise only one-fourth of the mapped study area: however, they contain one-half of the hazardous roof. This study determined that rock strength evaluations must be accompanied by underground observations. Suggested remedial support techniques include angled and/or longer tensioned bolts, steel mats or crossbars, steel sets or cribbing, and roof trusses.
Publication Date
19870101
Document Type
IH; Report of Investigations
Fiscal Year
1987
NTIS Accession No.
NTIS Price
Identifying No.
RI-9092
NIOSH Division
PRC;
Source Name
U.S. Bureau of Mines
State
PA;
TOP