In the Carrara Marble industrial extraction district the number of the under-ground quarries is increasing due to the convergence of several concerns: safety, environmental impact, mining optimization. These aspects led to the opening of large underground quarries. In 1994 rockburst phanomena occurred in two panels of the Carlone underground quarry,, which is located about 450 m below the topographic surface. In recent years a series of studies have been developed in order to understand and overcome the rockbursts. In this paper a detailed review of the geostructural and geomechanical setting of the Carlone quarry is presented along with a. 2D FEM analysis, both aimed at verifying the stress distributions around the underground openings during the excavation process, in order to better to understand the origin of the occurred rockburst.
The exploitation of Carrara Marble dates back to the Roman era, if not even further back to the Etruscans (Dolci 1980, Capuzzi 1984, Bruschi et al. 2004). In the last fifty years the rate of Carrara Marble exploitation has experienced a sudden increase, at present, about 4.5 Gtons of Carrara Marble is excavated every year, main-ly from a few large open pit and wide underground quarries. In the year 1973 a new underground quarry (Carlone quarry) was opened right in the middle of a tunnel of the old dismissed Marble Railway, which was excavated by drill&blasting in the last decades of the XIX century. In the early 1990's, two of the Carlone excavation panels suffered from localized rockbursts (Coli 1995, Ferrero et al. 2009, Coli et al. 2010, Gullì et al. 2010). A series of studies aimed at understanding the triggering mechanism of this phe-nomena have been carried out by the Authors in the last few years.