ANALYSIS OF THE ROOF AND PILLAR DESIGN IN ESTONIA OIL-SHALE MINES

This payer analyses the pillar and roof design in Estonia's oil shale mines, whew the roof-and-pillar mining is used. Numerical modeling was performed by the FLAC-program, using Mohr-Coulomb's failure criterion , average strength and elasticity parameters. The methodology for rock mechanics modeling in data limited conditions was exploited Analysis showed that the roof calculation method includes very large factor of safety. Tributary area method was used for pillar design. If is recomm ended to use a monitoring system for estimation the stability of a min ing block. Performed analysis and recommendations enable to improve th e underground design qualify in Estonia's oil shale mines.