Architectural and landscape evaluation of tunnel portals

Portal areas frequently represent some of greatest problems as far as the excavation of a tunnel is concerned. Many problems are concentrated in the portals, specially those that derive from the geologic nature of the ground, lack of confinement in the immediate overburden, and the rock. mass discontinuities. An increasing awareness of environmental problems over the last few years has drawn attention to preserving nature and, in the case of tunnels, limiting the damage to the ground to a level that is essential for the underground development. The environmental, architectural and landscape aspects connected to tunnel portals is analysed and discussed in this paper on the basis of a systematic comparison of different architectural solutions.