Retreat mining pillar stability.
Holmes Saf Assn Bull 1998 Nov; :15
Room-and-pillar retreat mining has been growing in popularity because of productive new technology, including remote control continuous miners, ex-tended cuts, and mobile roof supports. Pillar retreat mines can achieve the same high recovery as longwalls, with lower capital costs and greater flexibility. Unfortunately, between 1990 and 1995, nearly 30 percent of all roof and rib fatalities occurred on retreat mining sections. Also, millions of tons of minable coal are left in place each year because of pillar squeezes, floor heave, pillar line roof falls, and pillar bumps. Traditional pillar design methods are of little help due to the complex mining geometrics and abutment pressures that are present during pillar extraction
Mining-industry; Retreat-mining; Ground-control; Ground-stability; Coal-mining; Underground-mining; Room-and-pillar-mining; Mathematical-models; Analytical-processes; Computer-models; Geophysics
National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236
Holmes Safety Association Bulletin