Study on Mechanical Effect and Plastic Zone Distribution of Tunnel Surrounding Rock in the Presence of Various Expansion Approaches

Figure 10

Distribution of the plastic zone of surrounding rock in SEE. (a) Expansion of the excavation by 1.5 m. (b) Expansion of the excavation by 3.0 m. (c) Expansion of the excavation by 4.5 m. (d) Expansion of the excavation by 6.0 m.

(a)

(b)

(c)

(d)