Environmental Engineering Reference
In-Depth Information
Table 1.
Tunnel lengths and road lengths.
highway 2
×
2 lanes
expressway 1
×
2 lanes
Ribª
Brava s.
Vicente
Porto Moniz
Ribª Brava
calheta
Ponta do
Pargo
Machico
santana s.
Vicente
Ribª Brava
Funchal
Funchal
Machico
Machico
caniçal
Total
Total length of the road (m)
13995
20665
7770
34532
31805
33214
141911
Total number of tunnels
(including double and
secondary tunnels)
19
27
14
23
19
17
119
Total length of underground
road (m)
5981
4378
5096
23002
16305
13078
67840
Total length of underground
road/Total length of the
road (%)
43
21
66
67
51
39
48
200
181
180
160
150
154
142
140
120
94
100
80
60
Ancient Tunnels
40
34
20
0
1990 1992
19941996 1998 2000200220042006200820102012
Opening Ye ar
Figure 6.
evolution of the number of tunnels.
Figure 8.
Plan of the volcanic complexes.
The base volcanic complex β
1
, the older one, is
represented by different types of pyroclastic mate-
rials, with intercalations of basaltic lava, always
weathered to very weathered. Pyroclastic forma-
tions are coarse, with big angular blocks, volcanic
bombs, lapilli and ash. sometimes the fine pyro-
clastic materials (tuffs with bombs) are dominant.
The post-miocenic volcanic complex β
2
is very
heterogeneous and mainly consists of alternated
and irregular layers of compact basalts and com-
pact and disaggregated autoclastic breccias units
with variable thickness, interbedded, as well as
less significant compact tuffs. in general, the thick
basalts correspond to the most representative geo-
logical formation and concern basaltic rocks, of
high resistance, with gradual variation to vacuolar
basalts, from slightly to very vacuolar and more or
less breccious. They occur generally slightly weath-
ered or fresh, with moderate to wide fractures.
Fracturated or disaggregated basalts are generally
vacuolar or breccious formations, always more or
less fracturated or disaggregated, with weathering
60
200
181
53
52
180
50
160
140
40
120
30
100
80
18
20
16
60
40
88
6
10
4
44
4
20
2
1
1
0
0
0
0
Length of the tunnels (m)
Figure 7.
number of tunnels versus length of the
tunnels.
variations, provides a rock mass with a fairly het-
erogeneous character.
Madeira island comprises five volcanic com-
plexes as shown in Figure 8.
The main complexes are β
1
and β
2
.
