Road tunnels at Madeira Island, Portugal

The extremely mountainous and the heterogeneous volcanic rock formations of the Madeira Island led to the construction of an important road network where the tunnels are dominants. Unique and innovative solutions were also developed for multi-purpose hydraulic and hydroelectric systems. The road tunnels of new transport system of Madeira Island were strongly affected by the topography and by the land occupation. All these factors originate the design of a large spectrum of innovative structural solutions that permit to achieve economic solutions more adequate to the topographic and geological conditions. In the paper the analysis of a road tunnel between Canico and Camacha is also presented, along with the description of the construction and of the geotechnical information. An empirical system developed for volcanic formations is also presented.