Novel Excavation and Construction Method for a Deep Shaft Excavation in Ultrathick Aquifers

Figure 4

Construction procedure for the air shaft. (a) Dewatering and braced excavations. (b) Underwater excavation without drainage. (c) Underwater bottom-sealing construction. (d) Filling with low-grade concrete. (e) Shields passing through the air shaft. (f) Tunnel segments removed and construction of air channels.

(a)

(b)

(c)

(d)

(e)

(f)