Les cours pour la formation en matière des murs en pierre sèches sont organisés par l'association professionelle suisse des maçons en pierre sèche APSMPS. Pour les informations plus détaillées contactez le site www.trockenmaurer-verband.ch

Depuis quelques années, Stoneline maintient des contacts avec le Dry Stone Walling Association (DSWA) de Grande-Bretagne. (infos :http://www.dswa.org.uk. ) Tous les collaborateurs des Stoneline ont passé des examens de différents niveaux de performance chez les experts du DSWA. Ce coopération actif est représenté par des projets en Suisse et en Ecosse. Dieter Schneider (en mars) , Daniel Mettler (en juin) et Urs Lippert (en septembre) ont travaillé pendant cette année avec différentes personnes dans difféerents projets. Comme point culminant un pont a été construit par Norman Haddow et Dieter Schneider en mars 2003.

D'autres images : www.bigstoneman.freeservers.com

Stoneline ist dabei

32. International Geologcial Congress, Firenze, Italy

Marcel Stalder, Department of Geology, University of Stellenbosch South Africa
Daniel Mettler, Stoneline, Switzerland

Dry stone walls are a characteristic feature of many European cultural landscapes. The technique of dry stone masonry developed due to the general availability of natural stone as building material and the high cost of transporting mortar and cement to remote areas. The walls were constructed for a diversity of purposes and as such give testimony to a long tradition of man to cultivate and develop its natural environment. The most common type of walls are field walls and retaining walls, which subdivide pastures and support the typical terraced landscapes of many parts of Europe. In addition, dry stone walls act as foundations and provide support against erosion, floods and avalanches.
The aim of this contribution is to illustrate the influence of geology on the construction, appearance and stability of dry stone walls in selected areas of Europe, including Switzerland, the Aegean Islands and Southern Italy. Since the building material for the construction of dry stone walls is generally taken from a local source, the walls commonly reflect the ambient geological environment. In geologically heterogeneous regions, such as the Alps or the Aegean Islands, the geological diversity is often manifested by the presence of irregular and colourful random walls. In contrast, the geologically homogeneous Jurassic of Switzerland and the study area in Southern Italy are characterised by the occurrence of long and regular limestone walls. The physical characteristics of the rock influence the way building stones can be dressed and shaped. These prerequisites thereby control the building technique and ultimately the appearance and durability of the wall. Preferred building stones are competent rocks with planar internal structures (bedding and cleavage planes, joints), such as well-cemented sandstone, limestone and marl. The latter can be dressed into rectangular stones with good faces, which allow the construction of well-coursed regular walls. Hard and compact rocks, such as granite, massive gneiss and unjointed basalt, shatter unpredictably when dressed with a hammer or cannot be shaped at all. These stones result in the construction of irregular random walls. Apart from the quality of construction, the long term stability of dry stone walls is dependent on the resistance of the material against weathering. Collectively, the geological prerequisites thus control the beauty but also the deterioration of dry stone walls.