Fig. 6

Fracture morphology of overburden under disturbance during close distance coal seam mining: (A) W1143 excavation to balance, (B) W1145 excavation to balance, (C) W1121 excavation for 3000 steps, (D) W1121 excavation to balance.

Fracture morphology of overburden under disturbance during close distance coal seam mining: (A) W1143 excavation to balance, (B) W1145 excavation to balance, (C) W1121 excavation for 3000 steps, (D) W1121 excavation to balance.