The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

222 / 2018-07-15 21:16:10

Dr.

Coal pillar width, thousand-meter-deep coal mines, seismic loading, numerical simulation, convergence characteristics

Mine Dynamics Disaster > Rock burst impact

Coal burst is the main dynamic disaster in coal mining. Coal pillars of appropriate width play a significant role in controlling stress distribution and concentration level and thus in determining coal burst tendency. Numerical simulation and field measurement of the influence of a width-deceasing coal pillar on the convergence characteristics of a thousand-meter-deep exploration roadway were conducted to attain safe dimension for barrier coal pillars between panels and stop-line coal pillars. Results and analysis show that: (1) The mining-induced width-deceasing coal pillar successively experienced the Fully Stable Coal Pillar (FSCP) stage, the Partially Stable Coal Pillar (PSCP) stage, the Critical Coal Pillar (CCP) stage and the Yielding Coal Pillar (YCP) stage during the mining process; (2) the demarcation points of these four stages are approximately 100m, 40m and 10m. These results can be applied to coal pillar design in workfaces of similar conditions in the following approaches: (1) The priority in barrier pillar design is given to YCP, FSCP and PSCP in sequence; (2) The priority in stop-line pillar design should be given to FSCP, followed by PSCP on condition that the roof strata in the stop-line area are fractured and de-stressed in advance; (3) CCP should be avoided in both the barrier pillar design and the stop-line pillar design in all circumstances.