Evaluation of the impact of standing support on ground behavior in longwall tailgates.
Barczak-TM; Esterhuizen-GS; Dolinar-DR
Proceedings of the 24th International Conference on Ground Control in Mining, August 2-4, 2005, Morgantown, West Virginia. Peng SS, Mark C, Tadolini SC, Finfinger GL, Khair AW, Heasley KA, eds., Morgantown, WV: West Virginia University, 2005 Aug; :23-32
Longwall mines typically use some form of standing support for secondary roof support in longwall tailgate entries. Although there have been several new support products developed for this application, there remain no universal design criteria to optimize the application of these support technologies. The requirement for optimization and proper support selection is to understand the degree of control that the support has on the ground behavior. The ground reaction curve and numerical modeling were used to evaluate the impact of standing support on ground behavior. LaMODEL was used to evaluate the impact of standing support on main roof and floor behavior and pillar yielding. The conclusion drawn from this study was that standing supports do not have sufficient capacity to control main roof or floor loading or prevent the resulting convergence of the tailgate entry. However, it is imperative that this "uncontrollable convergence" be considered in the support design to prevent premature failure of the support. A FLAC model was used to evaluate the near-seam roof and floor behavior in conjunction with the global vertical and horizontal stresses. The model suggests that standing roof supports can have some impact on the ground behavior as the elastic response of the rock is exceeded and rock structure deteriorates from the stress concentrations that develop around the tailgate opening. During this phase, the capacity and stiffness of the standing support can be critical to the stability of the opening, as eventually the rock mass will be transformed into a partially detached structure whose weight must be supported by the standing support. This work is part of NIOSH's ground control program of research aimed at improving mine safety by reducing roof fall injuries and fatalities.
Ground-control; Injuries; Coal-mining; Safety-research; Hazards; Models; Computer-software; Mining-industry; Longwall-mining; Geology; Underground-mining; Geophysics
NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
Peng-SS; Mark-C; Tadolini-SC; Finfinger-GL; Khair-AW; Heasley-KA
Proceedings of the 24th International Conference on Ground Control in Mining, August 2-4, 2005, Morgantown, West Virginia