Civil Engineering Reference
In-Depth Information
Stage 1
Earthworks bund
Cut-and-cover tunnel
Ramp
Dewatered excavation
Stage 2
Tunnel element
Figure 13.7
Exposing the end of the cut-and-cover tunnel.
in the construction of the cut-and-cover section of the Limerick Tunnel in
Ireland, as shown in Figure 13.8.
Whatever method of construction is chosen, the seaward end of the tunnel
needs be fitted with a bulkhead and a gasket sealing plate. So, even with a
diaphragm wall or secant pile construction, it will still usually be necessary
to construct a short length of in situ concrete box so that the bulkhead and
sealing plate can be installed on the end to receive the immersed tunnel.
Then the existing river or sea wall will be removed to allow underwater
access to the exposed end.
