近距离煤层群下行开采过切眼岩层变形机理研究

Study on Deformation Mechanism of Rock Formation in Passing Openoff Cut During Descending Mining of Close Distance Coal Seam Group

张家峁煤矿进入煤层群联合开采阶段,上、下工作面层间距较小。受2个工作面采动共同影响,覆岩应力及位移变化规律区别于单一煤层开采。通过理论建模、数值模拟及现场实测等方法,分析了上煤层采动影响底板应力分布及位移变形规律,论证了上工作面过下工作面切眼时液压支架支护阻力未异常增大,上工作面推进经过下工作面切眼整个过程中,间隔岩层发生弹性形变,下工作面顶板离层出现短暂的愈合期。

Zhangjiamao coal mine has entered the coal seam group joint mining stage,and the distance between the upper and lower working faces is relatively small.Affected by the mining of two working faces,the variation law of overburden stress and displacement is different from that of single coal seam mining.Through theoretical modeling,numerical simulation and field measurement,the stress distribution and displacement deformation law of the floor affected by the mining of the upper coal seam are analyzed.During the whole process of the upper working face advancing through the lower working face incision,the interval rock strata undergoes elastic deformation,and the roof separation layer of the lower working face has a short healing period.