Civil Engineering Reference
In-Depth Information
Figure 8.7
Limerick Tunnel service building. (Photo courtesy of NRA/DirectRoute.)
distance from the tunnel portal and it is common to have separate buildings
to deal with the tolling operations.
Aesthetics
The architecture of the service building is likely to be important to the
local community. The location of the tunnel in terms of its urban or rural
environment will play a part in choosing the right approach. An example
is the Limerick Tunnel, which is seen in Figure 8.7, where because of the
low-lying area, the project owner desired that the tunnel building should
not protrude above the level of the flood protection bunds alongside the
River Shannon. This minimized the visual impact greatly and kept the
rural nature of the setting intact.
A number of tunnel projects have used naval architecture to influence the
form and appearance of the service buildings quite effectively. Where venti-
lation towers are required, it is difficult to minimize the visual impact, but
some tunnels have made a dramatic statement with the architecture rather
than trying to disguise them.
LAYOUT OF TUNNEL PORTAL AREAS
Determining the layout of the portal areas requires a number of functional
issues to be considered. These differ significantly between rail and highway
tunnels.
