EVALUATION OF PILLAR STRENGTH USING NUMERICAL MODELING, CASE STUDY: TABAS COAL MINE

9th International Multidisciplinary Scientific GeoConference - SGEM2009, www.sgem.org, SGEM2009 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 14-19, 2009, Vol. 1, 421-426 pp

ABSTRACT

Pillars are key structural columns in underground mining. They are usually made of in
situ intact ores and do not have additional reinforcements. Their main function is
temporary or permanent support of ore ceiling of rooms during excavation and mining.
Coal pillar strength is usually estimated according to empirical formulae obtained from
field observations. Todays, numerical models have found increasing use in pillar design.
The FLAC3D Software based Mohr-Coulomb Strain Softening (MCSS) failure criterion
was used to estimate pillar bearing capacity. By this study, it’s shown that pillars with
15 meter width in Tabas coal mine have 9.84 MPa strength and have the similar result
by Salamon and Munro formula.

Keywords: Pillar Strength, Coal Pillar, Mohr-Coulomb Strain- Softening