The project concerns one of the lots of the new ATG railway line in the Biasca area. The project concerns the construction of the artificial tunnel under the Biasca highway junction, as well as the refurbishment of the highway junction itself. It is a reinforced concrete structure approx. 250 m long, without wing walls, approx. 20 m large and almost 10 m high, divided into two pipes, one houses the two east and west tracks of the AlpTransit line and the other the overtaking track. The tunnel is curved, with variable slope, height and width, each segment is different from the previous one in dimensions and transversal and longitudinal slopes. For architectural reasons, maintaining the same geometry along the entire length, the project concerns 10% sloped walls.