Dewatering, waterproofing and drainage - Tunnel Engineering: Basics and Additional Services for Design and Construction - page 207

Experience with the use of grouting under very high pressure was gained during the con-
struction of the 23.5 km long drill and blast underwater section of the Seikan Tunnel
(overall construction period 1964 to 1984) in Japan [130]. A hydrostatic pressure of 24 bar
and the danger of seawater breaking in demanded extensive grouting with cement- and
waterglass-based grouts (Fig. 5-14).
Figure 5-14 Grouting
pattern in the undersea
section of the Seikan
Tunnel [158].
5.2.5.2 Ground freezing
Ground freezing can temporarily seal and consolidate the ground under conditions that are
water-bearing but not suitable for grouting. In contrast to grouting, the process only affects
the groundwater conditions during the construction period.
The process can be used with a soil water content of more than 156 % and a groundwater
speed of less than 1 to 3 m/d [130].
More detailed information about groundwater sealing can be found in [130, 153, 160].