Failure Depth of a Floor of a Fully Mechanized Working Face When Passing a Collapse Column

Figure 5

Plastic zone of surrounding rocks in the working face process: (a) working face 25 m ahead of the collapse column, (b) working face 5 m ahead of the collapse column, (c) working face above the collapse column, and (d) working face 10 m behind the collapse column.

(a)

(b)

(c)

(d)