shaft pillar

shaft pillar

[′shaft ‚pil·ər]
(mining engineering)
A large area of a coal or ore seam which is left unworked around the shaft bottom to protect the shaft from damage by subsidence.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The overall direction of mining is from the shaft pillar outwards, moving from raise line to raise line out toward the boundaries.
By August 1992, development on the Ventersdorp Contact Reef in the South Deep shaft-pillar area was completed, this allowed the stoping of the reef and stabilisation of the shaft pillar ahead of shaft sinking operations.