Special features of scheduling tunnel works - Tunnel Engineering: Basics and Additional Services for Design and Construction - page 295

Phase lb. After completion of the eastern temporary bridges, the north-south traffic was
diverted to the track area. This was followed by the temporary diversion of the sewer and
the installation of temporary bridges on the western side of the north and south station
heads.
Phase 2. This was the main construction phase. While the traffic ran over the temporary
bridges installed in Phases 1a and 1b, the construction site was set up between the tracks
and the launching shafts were sunk at the south and north station heads. The entire tunnel
was mined from these shafts. Meanwhile, the central bay of the DB bridge in the con-
struction area was installed, to be removed after completion. The construction area was
to be continuously accessible on foot from the site facilities areas through the southeast
entrance, which was provided with a temporary bridge.
Phases 3a und 3b. After the main part of the structure had been completed, individual traf-
fic was diverted back in lanes over the cleared central reservation. Finally, the temporary
bridges could be dismantled, the starting blocks finally completed and the surface demoli-
tion started.
Figure 7-15 Construction
schedule after one year of
work.