Numerical Analyses on Deformation and Failure Characteristics of Surrounding Rock of Gob-Side Entry Retention by Roof Cutting

Figure 12

Borehole televiewer detection results of roof rock fracture zones: (a) the section with 790 m offset from the open-off cut; (b) the section with 810 m offset from the open-off cut; (c) the section with 820 m offset from the open-off cut; (d) the principle of the borehole spreading pictures.