Study on Reasonable Layout of Upper Protective Layer for Prevention Rock Burst under Coal Seam Group with Close Quarters Conditions

Figure 12

Mechanical model of surrounding rock stress conditions in advanced segment of 3203 tailgate. (a) Spatial diagram of L-shaped stress superposition area; (b) A-A′ cross section. Note: 1-advanced abutment stress of gob 3203; 2-abutment pressure of side direction of gob 3201; 3-rock burst start-up zone.

(a)

(b)