The ground response curve, pillar loading and pillar failure in coal mines.
Esterhuizen E; Mark C; Murphy MM
Proceedings of the 29th International Conference on Ground Control in Mining, Morgantown, West Virginia, July 27-29, 2010. Barczak T, ed., Morgantown, WV: West Virginia University, 2010 Jul; :19-27
The response of the surrounding rock mass to the creation of mining excavations determines the ultimate load on a pillar support system. In conditions where the ground is relatively soft and weak, the full overburden weight can be transferred to the pillar system. However, in stiffer and stronger rocks, a greater portion of the overburden load is transferred to the unmined coal barriers or abutments, and the pillar stress is reduced. This paper makes use of numerical models to examine the interaction between typical pillar systems and the surrounding rock mass for weak and strong geological conditions at various spans and depths of cover. The concepts of structural failure and functional failure of pillars are used to assess pillar performance when pillars are deformed beyond their peak resistance. The results show that the span-to-depth ratio is an important factor in determining the pillar stress and the ultimate deformation of pillars. The ultimate pillar strain appears to be closely related to the functional success of pillar systems.
Underground-mining; Mining-equipment; Mining-industry; Room-and-pillar-mining; Ground-control; Ground-stability; Geology; Rock-mechanics; Stress
Conference/Symposia Proceedings; Book or book chapter
Proceedings of the 29th International Conference on Ground Control in Mining, Morgantown, West Virginia, July 27-29, 2010