近距离冲击煤层回采巷道防冲布置方式研究

Study on Layout of Mining Roadway to Prevent Rock Burst in Short Distance Coal Seam

针对近距离煤层条件下,上覆采空区边缘影响而造成下部煤层应力集中进而发生冲击地压的情况,以焦坪矿区下石节煤矿为工程背景,分析了下方被保护层4-2煤层回采巷道在不同位置时围岩应力分布情况及应力峰值变化特征,从防治冲击地压角度确定了被保护层回采巷道的合理位置。结果表明:开采边界区域造成的采动和卸压作用使得被保护层巷道两帮围岩应力呈现显著差异;当回采巷道位置从外错采空区向内错变化时,其围岩应力峰值逐渐降低;综合考虑降低冲击危险和保护煤炭资源,确定4-2煤层回采巷道内错20 m为防治冲击地压的合理位置。

The influence of the edge of the overlying goaf causes the stress concentration of the lower coal seam and then rock burst.Taking Xiashijie coal mine in Jiaoping mining area as the engineering background,the stress distribution of surrounding rock at different positions of mining roadway in lower4-2 coal seam is analyzed,and the reasonable position of mining roadway in protected layer is determined from the perspective of prevention and control of rockburst.The results show that the mining boundary and coal pillar make the stress difference between the two sides of the protected roadway;when the mining roadway moves from outside to inside,the peak value of surrounding rock stress decreases gradually;considering comprehensively reducing the impact risk and saving coal resources,it is determined that the 20 m internal dislocation of the mining roadway of coal seam 4-2 is a reasonable position.