NIOSHTIC-2 Publications Search

Yielding rock bolt holds promise for future ground control applications.

Authors
Conway-JP; Cox-DJ; Gooch-AE
Source
Min Eng 1977 Apr; 29(4):53-55
NIOSHTIC No.
10001055
Abstract
A 2-year test conducted by the Bureau of Mines Spokane (Washington) Mining Research Center (SMRC) has proven the feasibility of the yielding rockbolt, a concept which may prove very useful to the mining industry by providing ground support under a variety of conditions. The yielding rockbolt was originally developed in South Africa to overcome the limitations of conventional bolting in rock subjected to high-stress or rock burst conditions. The yielding effect is obtained by fitting the bolt prior to thread rolling with a smooth-bore die of internal diameter slightly larger than the shank diameter but smaller than the rolled thread diameter. Prior to field testing, the SMRC-designed bolt and the South African design were compared for ease of installation at the SMRC test adit. Both designs use the thread-die yielding concept, with the only difference being the position of the die. Although no difficulties were experienced in the installation of either type, the SMRC design was chosen because (1) installation was easier and faster with the kinds of equipment used in U.S. mines, (2) any type of standard or resin point anchor could be used, and (3) with the collar at the plate end, observation and measurement of the protruding threads gives an estimate of ground movement.
Keywords
Mining-industry; Underground-mining; Ground-control; Engineering-controls; Control-technology
CODEN
MIENAB
Publication Date
19770401
Document Type
OP; Journal Article
Fiscal Year
1977
Identifying No.
OP 43-77
Issue of Publication
4
ISSN
0026-5187
NIOSH Division
SRC
Source Name
Mining Engineering
State
WA
Page last reviewed: March 11, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division