Mining Publication: Observations and Evaluation of Floor Benching Effects on Pillar Stability in U.S. Limestone Mines
Original creation date: May 2007
A survey of roof and pillar conditions in underground limestone mines in the United States has revealed that bench mining of the floor between pillars can cause instability in the pillars at the perimeter of the benched area. Increased loading of these pillars was observed at several mines. Large inclined geological structures that are exposed in pillar ribs were observed to contribute to pillar instability. The paper describes a study that was carried out using numerical models to assess the effects of bench mining on pillar load and stability. It was found that the benched pillars shed load onto the surrounding pillars owing to their reduced stiffness. The pillars at the perimeter of the benching area will start shedding load as soon as benching increases the height of one side of the pillar. A case study is described which shows the effects of bench mining on limestone mine pillars.
Authors: GS Esterhuizen, DR Dolinar, JL Ellenberger
Conference Paper - May 2007
NIOSHTIC2 Number: 20032394
In: Eberhardt E, Stead D, Morrison T, eds. Proceedings of the First Canada - U.S. Rock Mechanics Symposium (Vancouver, British Columbia, Canada, May 27-31, 2007). Taylor & Francis Ltd., 7 pp.
See Also
- Assessment of Stable and Failed Pillars in Underground Limestone Mines
- Coal Bumps and Odd Dynamic Phenomena - A Numerical Investigation
- Effect of the Dip and Excavation Orientation on Roof Stability in Moderately Dipping Stone Mine Workings
- Effects of Weak Bands on Pillar Stability in Stone Mines: Field Observations and Numerical Model Assessment
- Evaluation of the Effects of Length on Strength of Slender Pillars in Limestone Mines Using Numerical Modeling
- Failure Characteristics of Roof Falls at an Underground Stone Mine in Southwestern Pennsylvania
- Investigation of Pillar-Roof Contact Failure in Northern Appalachian Stone Mine Workings
- Pillar Stability Issues Based on a Survey of Pillar Performance in Underground Limestone Mines
- Sizing of Final Stumps for Safer Pillar Extraction
- Stability Analysis of a Backfilled Room-and-Pillar Mine
- Page last reviewed: 9/21/2012
- Page last updated: 9/21/2012
- Content source: National Institute for Occupational Safety and Health, Mining Program