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

Field verification of load transfer mechanics of fully grouted roof bolts.

Authors
Signer-SP
Source
Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9301, 1990 Jan; :1-13
NIOSHTIC No.
10007449
Abstract
The Bureau of Mines conducted a series of field tests to improve the understanding of the support interaction mechanics between fully grouted bolts and coal mine roofs and to help lay the foundation for improved design and evaluation techniques. Strain gauges were installed on 14 fully grouted bolts placed in shale roof rock at four mines in Colorado, Illinois, and Pennsylvania to determine how load was transferred between the bolts and the rock. The results of field tests on elastic bolt behavior compared well with previous laboratory work and numerical models. The field tests showed that the anchorage length of grouted bolts installed in shale was slightly longer than the anchorage length determined in laboratory tests conducted in concrete blocks. The field results produced more variability because of geological variations. Tests run past the yield point of the steel bolt indicate that the yield zone varies significantly and translates down the length of the bolt anywhere from 4 to 22 in.
Keywords
Mining-industry; Rock-mechanics; Rock-falls; Underground-mining; Coal-mining
Publication Date
19900101
Document Type
IH; Report of Investigations
Fiscal Year
1990
NTIS Accession No.
PB90-225871
NTIS Price
A03
Identifying No.
RI-9301
NIOSH Division
SRC
Source Name
Spokane, WA: U.S. Department of the Interior, Bureau of Mines, RI 9301
State
WA; CO; IL; PA
TOP