A new method for yield pillar design to control coal bumps.
NIOSH 2003 Sep; 1-187
Coal mine bumps have presented serious mining problems in the United States throughout the 20th century. Also, it is anticipated that as the easily recoverable reserves are depleting, the trend will be toward deeper mines. Current practice of yield pillar applications shows that it can prevent coal bumps in some long wall mines and safe coal reserves for deep mines. The current methods of yield pillar design size the yield pillar just to be yielded without considering the pillar instability after it yields. The coal bumps problem arises after the pillar yields. Finite Element technique is a good approach to simulate the complex loading conditions of the yield pillar systems. Unfortunately most of FE commercial codes are not designed for mining applications. Therefore an adoption for any implemented FE code should be an essential step towards a rational design method. Finally, a computer-based program which can design stable yield pillar systems for most common geological and geometrical conditions would be extremely useful. In this work coal pillar and gob models were developed. The key issues of the newly developed method, it evaluates the pillar stability in post-peak region also it divides the yield pillar into three loading zones; namely core, transition and rib zones. An appropriate stability criterion was assigned for each zone. An interpolation model for the pillar stability measures based on a full factorial analysis for the geological and geometrical factors was developed. A PC-program was established based on a proposed design algorithm and the developed interpolation model. This program is able to design and evaluate the 2-entry yield pillar systems.
Coal-mining; Mining-industry; Occupational-hazards; Engineering-controls; Engineering; Models; Rock-bursts; Rock-falls; Rock-mechanics; Geology; Ground-control; Ground-stability
Mining Engineering Department, West Virginia University, PO Box 6070, Morgantown, WV 26506-6070
Final Grant Report
National Institute for Occupational Safety and Health
West Virginia University Research Corporation, Morgantown, West Virginia