Torino Hut Tunnel
The facilities have the dual function of structurally anchoring the new Pointe Helbronner station to the rocky substrate and of hosting safety staircases and elevators (13 passengers, 1000 Kg load capacity) that will connect with the pedestrian tunnel leading to the Torino Hut, since the new project will no longer stop near the hut.
The vertical well will be approximately 70 meters deep with a finished internal diameter of 5 metres and will be created using a 40 cm diameter pre-bored hole created with the “Raise Boring” technique, which is characterized by the precision of its diameters, the integrity of the walls (since they are not affected by explosions) and by the possibility of constantly removing debris that accumulate at the base of the wells during the work. This hole will then be widened and covered with a layer of concrete of a thickness ranging between 0.5 and 1 metre.
At the base of the well, a large chamber will be created for hosting the elevators, stairwells, well extension and the water accumulation tank for supplying the fire-fighting system. The water accumulation tank will be designed with a heat insulating layer in polystyrene coated with a thin layer of reinforced concrete with a thickness of 10 cm finished with osmotic plaster.
The structure therefore consolidates the whole mountain section where the new station is to be erected and allows properly anchoring the cableways load bearing structures, considering that its cables bear over 100 tons of tension each, and will be anchored to specifically designed reinforced concrete drums.
The pedestrian tunnel has a 15 m2 excavated section and is approximately 154 metres long. It includes a natural cave segment of 143 metres and an artificial tunnel segment of 11 metres near the exit to the Torino Hut. The natural gallery is supported by framework and this area will not be faced with reinforced concrete. The last section of the tunnel is designed with fields of micro-rods and metallic framework covered in a thin layer of reinforced concrete.
The tunnel, besides serving as a well-lit connection between the station and the Torino Hut, also serves as a place to house electrical, heating and water systems in their own special compartments.