Environmental Engineering Reference
In-Depth Information
and eight tunnels in the direction of the airport.
The landmark was the river João Gomes crossing
(north of Funchal) with double tunnel João Gomes,
cut and cover Jardim Botânico tunnel and the
three lane Pestana Júnior tunnel. Figures 2 and 3
show these three tunnels in the interconnection to
Funchal.
in 2000 there was a spectacular evolution on
construction, with a total of 60 tunnels concluded,
with two important tunnels, the encumeada tunnel
and the norte tunnel, to the north of the island
airport prolongation works were also concluded
in 2000. The roadway travel time from Funchal to
airport was reduced from 40 min to 15 min.
in 2004 the construction of more 48 tunnels was
concluded, including the longest road tunnel of
Portugal (Faial-cortado) and the longest double
tunnel of Portugal (caniçal tunnel). in Figure 5 is
shown the east portal with three lanes. The har-
bour of caniçal was also constructed in 2004.
currently 27 tunnels are under construction.
Figure 4.
santa cruz tunnels.
Figure 5.
Double caniçal tunnel east portal with three
lanes.
Table 1 shows the importance of tunnel's length
when compared with the total length of the roads.
We can observe that about 36% of the total length
of the highway Ribeira Brava-caniçal is crossed
in tunnel. in a reduced length of this highway,
between Machico and caniçal, with 7,8 km exten-
sion, 66% of the road is underground. For the
express ways this relation is about 52%.
The evolution of the number of road tunnels
constructed in the last 16 years (between 1994 and
2010) is shown in Figure 6. on average about 10
tunnels are constructed a year.
in Figure 7, where is presented the number of
tunnels versus the length of the tunnels, is interesting
to verify that a number of 69 tunnels have a length
greater 500 m (35% of total number of the tunnels),
11 tunnels have a length greater than 2000 m and
two tunnels have a length greater than 3000 m.
Figure 2.
Plan of João Gomes river crossing.
4
GeoloGical anD GeoTechnical
asPecTs
The lenticular and layered structure of volcanic
formations, including more or less disaggregated
fractions, as well as frequently abrupt lythological
Figure 3. aerial view of João Gomes river crossing.
