The Cava Madre of Candoglia: The Centuries-Old Cavern from which the Marble is Extracted for the Construction and the Perpetual Conservation of the Milan Cathedral

The Cava Madre of Candoglia is a centuries-old mining cavern of significant historical-architectural interest because it is the site from which the marble is extracted for the renovation of the external structure of the Milan Cathedral. This activity is continuous and therefore requires the guarantee of the supply of the same marble that was used for the construction of the Cathedral. Over the time, block extraction and handling techniques have changed and evolved, ensuring their effectiveness and safety. Today diamond wire is used to detach the bank and to cut the blocks. The movement takes place using trucks capable of traveling along the access road to the quarry and transporting the blocks to the processing laboratories. Some geomechanical aspects play a fundamental role: a careful characterization of the rock materials (marble vein and embedding rocks) in the laboratory and on site, a reliable numerical modeling capable of representing the evolution of the stresses and deformations in the rock and in the present support and reinforcement structures, continuous geomechanical monitoring to control the state of stresses and deformations that actually develop in the rocks and support structures.