Validation study of no-pillar mining method without advance tunneling: A case study of a mine in China

Abstract

Studies regarding the reuse of a gob-side roadway formed by the N00 longwall mining method are scarce. To investigate the mine pressure behavior characteristics during roadway reuse, the anchor cable force, roof-to-floor deformation, and working resistance of the hydraulic support obtained from the verification working face were analyzed. Test results show that the influence range of the mining-induced pressure was 0-90 m in front of the working face. The ratios of the first and periodic weighting steps between the entry-retaining and non-roof-cutting sides were 20.25 and 1.94, respectively. However, the ratios of the ground pressure strengths at the two sides were 1.07 and 1.31, respectively. The results indicate that the monitored roadway can be classified into three deformation zones based on the severity of the mine pressure behavior: large, intermediate, and creep. The main roof between the adjacent working faces exhibited a failure type comprising the “O-X” and “O-Y” states, which resulted in an unconventional mine pressure behavior. This study provides insights into the N00 longwall mining method as well as important guidance for tackling similar geological conditions when using this mining method.