Influence of Support Parameter and Excavation Methods on Statistical Distribution Characteristics of Surrounding Rock Pressure in Shallow-Buried Metro Tunnel

Figure 6

Process of excavation by sections: (a) excavation step 1 and support, (b) excavation step 2 and support, (c) excavation step 3 and support, (d) excavation step 4 and support, and (e) remove temporary support.

(a)

(b)

(c)

(d)

(e)