Underground dimension stone quarrying: Rock mass structure and stability

The paper examines some cases of dimension stone quarries in different basins in Italy. In these quarries, technical and economic features induced the managers to change the exploitation method from open pit to underground or to begin underground exploitation. These facts are mainly due to the type and origin of the rock and its characteristics, both from the structural point of view and also taking into account the influence of the lithological features on the quarrying technologies and underground structures stability. With the aim of defining the stability conditions of the structures, it is interesting to look for links between the geostructural situations and the planning of quarrying activities, improving both the safety conditions and the productivity of the quarry. The design of the exploitation of underground dimension stone quarries is therefore based on geomechanical, technological, economical and environmental aspects. The paper examines two significant cases: green ophicalcites (Aostan Alpine Range) and the arabesqued marble (Apuane Alps), both in Italy. The aim of the study is to furnish some design elements in order to define the underground structural pattern and the more appropriate criteria for the stability analyses of the quarry openings.