3. Diaphragm Wall Construction
Long sections of the cut and cover use diaphragm walls to support the sides of the open excavation, while work on the relocation of services and the construction of the in situ horse-shoe tunnels takes place. Once cast and set, the Tunnels are completely self-supporting and are not dependent on the diaphragm walls for structural stability.

4. The equipment used for excavation of diaphragm wall

6. Construction sequence of a slurry trench
This type of wall, known in North America as "slurry trench", is a cutoff wall made of a mixture of bentonite and aggregates. A fairly wide trench (commonly 5 ft) is excavated under bentonite slurry. Excavated materials (aggregates) are placed in the trench in such a way that the backfilled aggregates form a gentle slope in the opposite direction from ongoing excavation. To ensure an effective cut-off effect, slurry trenches must be rather wide so as to compensate the possible defects due to the simple dumping procedure.
Construction sequence of a slurry trench

10. ˈˈ Rock foundation treatment
for dams
ˈˈ Rock cutoff curtains
ˈˈ Pressure injected anchors
ˈˈ Ground treatment for
tunneling applications
ˈˈ Void filling in mines