Physical Modeling of a Shallow-Buried Metro Tunnel in the Soft Loess Layer Using Similarity Theory

Figure 8

Surrounding rock stress variation of the CRD-4 excavation method under different pre-reinforcement forms. (a) Section I excavation. (b) Section II excavation. (c)Section III excavation. (d) Section IV excavation.

(a)

(b)

(c)

(d)