Construction en pierre massive en Suisse

«For me, to build an air terminal with stone would be a stupidity, not to say a madness. But to use dynamic structures to fit three-roomed flats with kitchen in buildings from three to ten floors, is not less aberrant.»1 Provocation of a reactionary architect or a lucid analyze of the world of the construction of his time, this assertion of Fernand Pouillon still preserves, forty years after, its value of interrogation on the use of the natural stone. Indeed, since the industrial revolution and the introduction of new construction materials, like concrete and steel, the natural stone was gradually confined in the sphere of the noble claddings. If we look at behind, on the other hand, until the 19th century, we realize that the situation was very different, as well the use of this material as its social status. The stone was, and it still is, thanks to its great durability, the principal constituent part of the built environnement: public buildings, simple rural buildings, civil engineering works, cadastral limits and limits of properties, all were made out of natural stone, a material largely available locally, at least in our countries, and whose exploitation required reduced energy investments. The local builders knew, in an empirical way, the characteristics of the rocks they had as much to facilitate their extraction, by exploiting the natural fractures and "weaknesses", as for their selection. Thanks to their resistance to the atmospheric agents, increased by the strong thicknesses used, the cut stones could be employed again. The investment in work and energy was thus amortized on several generations. An adequacy between the resource, the exploitation and the techniques occurred naturally. In a slow evolution, the natural stone arrived until the industrialization of the processes of exploitation and shaping and allowed in France, in the years of the post-war period, to rebuild cheap blocks of flats by using a "pre-cut stone" with standardized dimensions. After the end of this "adventure", the use of natural stone in massive form slowly disappeared, to reappear in the years 1990, when the French architect Gilles Perraudin started to employ again dimensional stone, simply cut in the quarry, for the construction of buildings of various use. Our PhD thesis fit into the tradition of the experience of Fernand Pouillon. Indeed, today, at the era of sustainable development and the energy diaries, the use of natural stone as building material should be restored. Accordingly, we treat in this research the case of massive stone construction in Switzerland. While following the course which leads the natural stone of the mountain to the building, we tried to define a method to use dimensional stone in the current construction industry, while respecting the current constraints as regards durability, seismic safety and reduction of energy consumption. We thus tried to show that the natural stone can continue to be regarded as a whole construction material