Behaviors and Overlying Strata Failure Law for Underground Filling of a Gently Inclined Medium-Thick Phosphate Deposit

Figure 7

(a) Fissures appeared in the rock strata of the third-level mining approach. (b) Promotion of the sixth-level mining approach directly above the avalanche. (c) Promotion of the collapse of the top slab of the tenth-level mining approach. (d) The roof collapses after the mining is completed.

(a)

(b)

(c)

(d)