Assessment of the stability conditions of ancient underground quarries through on site monitoring and numerical modelling

This work, carried out by members of the University of Parma’s Department of Civil and Environmental Engineering and Architecture, analyzes the stability of the ancient underground quarries at Viggiù (Varese, Italy). The objective of the study was to verify the actual structural predisposition to instability phenomena in the ancient ornamental stone quarries for a historical and cultural valorization as well as the recovery of the Danzi and Beltrami quarries. Although completely abandoned, these sites could be used as a tourist attraction and/or as a teaching environment. They are a wonderful example of industrial architecture, presenting audacious compositions of filled-in trenches and room and pillar techniques (Hedley and Grant, 1972). With such objectives in mind, a monitoring system that aims to control the most significant joints and discontinuities of the site has been realized. A numerical model of the entire rock mass has been developed in order to analyze the stability of the underground openings. A route for visitors has also been identified.