Controlled excavation for new lift shaft in confined space, Cortabbio Mining Park

The Cortabbio Mining Park in Primaluna, located in Cortabbio, is an ancient baryte (barium sulphate) mining site that runs through a complex system of underground tunnels.
In the past, access to the different levels of the mine was via horizontal and vertical tunnels connected by stairs. With the subsequent transformation of the site into museum structure and guided tour route, it was necessary to improve accessibility between levels by implementing a lift of approximately 7 metres in height inside the main gallery.

The earthworks necessary for the construction of the lift shaft presented important operational limitations, due both to limited space and the impossibility of using internal combustion vehicles to avoid air pollution in a confined environment.
First, a thorough planning of the intervention was carried out, defining the working area and assessing the volume of material to be removed. Next, the work front was prepared, by means of vertical cuts about 40 cm thick, spaced about 30 cm apart, executed with ramped diamond cutters for sectioning the rock, the operation was repeated progressively until a depth of approximately 2.50 metres was reached.

Once the portions to be removed had been delimited, controlled demolition was carried out: the sectioned rock masses were broken up with the help of the electrically controlled radio-controlled robot, which ensured precision and safety even in limited space conditions. The crushed material was then loaded onto trolleys and removed from the work area using quarry carts, resulting in a total volume of approximately 40 m³ of demolished rock.