Pillar Design In Underground Oil Shale Mines

Abstract

The Colony pilot mine provided valuable pillar strengths that should form the basis of any subsequent mine designs. As no commercial oil shale mine has yet been developed, neither a comprehensive empirical pillar strength formula can be developed, nor a proposed empirical formula tests. This study summarizes the strength data available for oil-shale pillars and suggests a strength formula similar to that in common usage for coal pillar design, but with constants compatible with the pillar strength available data in oil shale. Confidence in the use of this formula is limited to situations where the ground conditions are similar to that at the Colony pilot mine, so in application of this formula to a new oil shale area, a comprehensive geotechnical data collection program must be undertaken so that a valid comparison can be made. The study points out the possible conservation nature of the strength formula for barrier pillar design where the pillar width to height ratio is high. (16 refs.)