Mechanical and Coal Burst Breeding Mechanism of Coal Samples under True Triaxial Loading and Unloading

Figure 11

The energy density nephogram and shock sources at different stages: (a) loading to the triaxial stress stage; (b) true triaxial loading and unloading experimental stage I; (c) true-triaxial loading and unloading experimental stage II; (d) high-speed unloading stage (coal burst experiment); (e) burst source location diagram.

(a)

(b)

(c)

(d)

(e)