- Equipment, tools, and parts
- Geographic regions
- Geologic conditions and events
- Hazard prevention and control
- Hazards and exposures
- Mine locations, excavations, and structures
- Mining types and methods
- Population groups
- Products and materials
- Research disciplines
- Research methods and measures
- Tasks and activities
- Document types
Results 21 - 30 of 52
A unique circumstance created by monitoring a pre-driven longwall recovery room permitted measuring the stresses of a coal pillar throughout its entire life cycle in less than a week. The complete transformation took place in less than 12 hours.
Effects of Weak Bands on Pillar Stability in Stone Mines: Field Observations and Numerical Model AssessmentObservations of pillar conditions in limestone mines showed that the presence of weak bands in the limestone can result in pillar damage. This study investigated the mechanism of failure caused by the presence of weak bands using numerical models.
Evaluation of the Effects of Length on Strength of Slender Pillars in Limestone Mines Using Numerical ModelingNumerical modeling is used to evaluate the degree the pillar strength is increased with a rectangular pillar over a square pillar.
A detailed evaluation of the multiple-seam experiences at Harris No. 1 Mine was done as part of NIOSH's nationwide multiple-seam mining case history database.
Multiple-seam interactions are a major ground control hazard in many U.S. underground coal mines. NIOSH has been conducting research to develop better techniques for predicting the location and severity of multiple-seam interactions.
5/1/2007 - Conference papersA survey of roof and pillar conditions in limestone mines has revealed that bench mining of the floor between pillars can cause instability in the pillars at the perimeter of the benched area. Numerical models were used to assess those effects.
1/1/2007 - Peer reviewed journal articlesSome of the issues affecting pillar strength at low width-to-height ratios in hard, brittle rock are investigated. The results showed that the strength of slender pillars is more variable than that of wider pillars.
8/1/2006 - Conference papersA survey of pillar conditions was carried out at 21 operating limestone mines that use the room-and-pillar method. Pillar instability is most likely caused by unfavorable geological structures in pillars with width to height ratios of less than 1.5.
3/1/2006 - Technology NewsThe use of highwall mining systems has increased substantially in open-pit coal mines. It is used where overburden depth exceeds economical recovery. Highwall stability remains the major safety concern during highwall mining. The Mine Safety and Health ...
Analysis of Highwall Mining Stability - The Effect of Multiple Seams and Prior Auger Mining on Design8/1/2005 - Conference papersThe objective of this is paper is to review the current state of knowledge and practice in highwall mining.