Study on Failure Characteristics and Reasonable Mining Parameters of Upward Mining of Integrated Coal Mine

Figure 21

The change of plastic zone in two sides of roadway in 302 mining area when the cutting position is 380 m ahead of schedule. (a) Working face advancing 40 m; (b) working face advancing 80 m; (c) working face advancing 120 m; (d) working face advancing 160 m.