Strata Behavior and Principal Controlling Factors Analysis of Working Face Under Upper-stratified Coal Pillar Group

For thick coal seam mine, the residual coal pillar group and empty roadway formed by upper-layer irregular mining caused difficulties for lower-stratified mining. To improve the recovery rate of the coal resource, distribution laws of mine pressure under upper-stratified coal pillar group was studied. By tracking the pressure value of 7408 woking face in Maozequ old pit mine during tunneling process. The pressure data shows the unknown-location and value fluctuations are the main characters under this situation, and the numerical simulation shows that the main effect factors include size of residual coal, size of empty roadway and strength of bearing medium. Finally, the article proposed targeted mining suggestions.