ABSTRACT: The main feature of aquifers in volcanic islands with high rainfall rates and steep topography is that they are on raised, mainly due to the presence of volcanic dikes. Dikes are igneous bodies with very high aspect ratio, which means that their thickness is usually much smaller than the other two dimensions and tend to be vertical or of high dip angle. It can be considered as impermeable and interconnected walls where aquifers, which are recharged by rain, raise the water table between the dikes. This is especially important in volcanic rift zones. The method to obtain water in these volcanic areas involves digging horizontal galleries with explosives. The galleries cross the dikes and drain the water from the water saturated area. The main problem of this type of perforation is to obtain the water continually, without the possibility of water regulation. This question has been solved by means of the reconstruction of several technically viable dikes, to enable the store of water resources through channels in order to regulate the water wealth of the built galleries. Methods, results and viability on the use of the volcanic materials as relevant works of civil engineering highlights on the following paper.

ABSTRACT: Chillida's visionary artwork to create a large Space in the Tindaya Mountain represents a big technical challenge. On the one hand, dimensions of the span and flat profile of the cavern roof are unique in underground engineering. On the other hand, the transmission of the artist's idea and the realization of an aesthetic concept combining art, technique and nature in a natural way will require an innovative support solution.

ABSTRACT: This paper presents the work done to recovey the historical Fuente Santa spring, well known at Middle Age due to its miraculous medical effects. The spring was buried by San Antonio volcano eruption in 1677, with debris, cinders and lava flows. A gallery was recently excavated under extreme and difficult natural conditions, a total lack of stability with granular materials involved. The direction of the axis of the gallery was initially unkown.

ABSTRACT: Due to the existing conditionings for the implantation of the different areas that comprise Cabo Girão Tourist Resort, at Madeira Island, namely the vigorous relief and the geological-geotechnical conditions, it was necessary to conceive an important group of retaining structures, using different solutions, varying from gravity and semi-gravity cyclopean concrete structures to reinforced concrete walls and soil nailed walls or nailed slopes. This paper presents the conception of the project in its different stages and the main activities developed under the scope of the special technical assistance provided during the execution phase.

ABSTRACT: The Machico-Caniçal Expressway, 8 km in length, is part of the Madeira Island's new development program, which connects Funchal city to Caniçal village via a continuous expressway along the island's southern coast. This expressway crosses an extremely mountainous region affected by the existence of two very heterogeneous geological volcanic complexes, generally covered by unstable slope deposits or by thick alluvial deposits, leading to the construction of a wide range of civil engineering Works. This paper presents the main aspects related with the design and construction of six double tunnels along the referred expressway, as well as a number of safety aspects related to these tunnels.