Dynamic Phenomenon in Coal Mine Roadway Boundary and Supporting Adjustment in Bursting Condition

The boundary magnification phenomenon was achieved in the coal mile surrounding rock, the displacement of surrounding rock was gradually increased, then more gentle in the plastic zone and sharply increase in the broken zone. The overall process of the displacement of surrounding rock exhibited graded changing trend; when the impact came, the broken zone had connected fissures caused by stretch of waves. It eventually increased the degree of...