Application of blasting and pressure relief of reserved coal pillars along the inclined coal seam

In order to solve the stress concentration caused by the lateral stress of the gob below the air inlet roadway in the West Wing I010203 face of Kuangou Coal Mine, a comparative analysis of on-site coal stress gauge monitoring data and non-dimensional data processing were adopted. The combined methods were used to study the stress distribution of surrounding rock on the side roadway with reserved coal pillars along the gob. Research results show that: The stress distribution of the upper side of the roadway in the air inlet roadway along the gob is different from that of the lower side of the roadway. The stress in the shallow part of the upper side of the roadway is positively correlated with the working face distance, the coal body stress concentration is the highest at the hole depth of 4.5 m. The stress concentration is distributed in the range of 50～110.6 m in the advanced working face，and the significant influence range is within 50 m ahead of the working face; the deep part of the coal body on the lower side of the roadway is higher than the shallow part and is positively correlated with the distance of the working face, and the coal body stress concentration is located at 9 m, and the mining stress concentration is in the range of 50～80 m in the advance working face, and the significant influence range is within 60 m ahead of the working face; the pre-pressure relief range of upper side in the air inlet roadway along the gob is 50～120 m, and that of lower side is 60～80 m. With reference to empirical data and theoretical calculations, the relevant parameters of the upper coal body blasting pressure relief project and the lower coal body large straight borehole pressure relief project of the air inlet side roadway along the goaf are determined, combined with PASAT detection and surrounding rock stress data. Comparative analysis results show the designed coal body blasting pressure relief project can effectively reduce the stress concentration of surrounding rock of the reserved coal pillar, but the large diameter pressure relief borehole should ensure a certain amount of work and form a continuous pressure relief surface to achieve the expected pressure relief effect.