Road tunnel design and construction at Madeira Island - Volcanic Rock Mechanics - page 260

Road tunnel design and construction at Madeira island

J.M. Brito, c.J.o. Baião & s.P.P. Rosa
Cenorgeo, Engenharia Geotécnica, Lda., Lisboa, Portugal

aBsTRacT: in the last two decades a new fundamental road network was undertaken at Madeira
island. Due to the vigorous relief of the island, the great heterogeneity, the structural and lithological
complexity of volcanic rock formations and to the land occupation, tunnels became dominant and a
large spectrum of innovative structural tunnel solutions were developed. The objective of this paper is to
give a global vision of the importance of this group of infrastructures, focusing in the new fundamental
road network evolution and construction of road tunnels at the island and in the conception and design
aspects, along with the description of the geological-geotechnical conditions, primary and secondary
lining, phased construction and monitoring.

1 neW FUnDaMenTal RoaD

neTWoRk

in the last two decades, in order to improve the
road accesses from Funchal city to the main vil-
lages, due to the increasing development, a new
fundamental road network was undertaken at
Madeira island.
it was the most important investment in Madeira
history, over 2000 × 10 6 €.
This accessibility plan was implemented by the
construction of the priority highway (via rápida
VR1) Ribeira Brava-Funchal-caniçal in the south
of the island ( Fig. 1 ) . This important highway, with
2+2 lanes, allows the liaison to the airport of santa
cruz and to the port of caniçal. The construction
began in 1989 and was completed in 2004, with a
cost of about 800 × 10 6 €.
actually the fundamental road network of
Madeira is also constituted by express ways (vias
expresso—Ve) with one lane in each direction plus
one slow lane where necessary ( Fig. 1 ).
With the ancient road network, also represented
in Figure 1, to go from the capital Funchal to Porto
Moniz in the northwest, 3 hours were necessary.
Today only 45 min are needed.
actually the main regional road system length is
about 200 km, with about 85 km in tunnels.

Figure 1. Fundamental road network of Madeira island.

allow an acceptable level of comfortable accessi-
bilities to the main villages of the island.
in order to achieve more adequate and econom-
ical solutions to overcome the topographic and
geotechnical conditions, a large spectrum of inno-
vative structural tunnel solutions were developed.
The great number of tunnels is a result of
the geomorphology which imposes important
restraints. While the european Directive (european
Parliament, 2004) defines a maximum longitudi-
nal pendant of 5% (except where geographically
impossible), in Madeira exist tunnels with pen-
dants from 8,5% (Pontinha tunnel) to a maximum
of 13% (Pestana Júnior tunnel).

2 The iMPoRTance oF The TUnnels.

concePTion anD DesiGn asPecTs

3 consTRUcTion eVolUTion

oF RoaD TUnnels

Due to vigorous relief of the island, the great het-
erogeneity, the structural and lythological com-
plexity of volcanic rock formations and to the land
occupation, tunnels became dominant, in order to

at the first phase of the new roads, 20 tunnels were
constructed to the West side of Funchal in direc-
tion to Ribeira Brava, with two important double
tunnels, Quinta Grande and Ribeira Brava tunnels,