INSTABILITY MECHANISM AND PREVENTION OF ROADWAY UNDER CLOSE-DISTANCE SEAM GROUP MINING

During the process of close-distance seam group mining,mining roadway in the lower seam is affected by coal pillar in the upper seam and the adjacent working face′s mining. Due to the severe roadway roof caving and floor heave in the working face E12505 in Cuijiazhai coalmine,the field measurement,theoretical analysis and numerical simulation are adopted to study the mechanism of roadway′s instability. The result shows that,when the upper pillar...