ABSTRACT
The choices and solutions adopted for the construction of the Merano’s ring road system, are presented. It consists of an urban tunnel approximately 3,400 m long, of which 1,200 m carried out with cut & cover method in loose soil, and 2,200 m with conventional mining methods. This latter stretch is about half in loose soil and half in rock. The portion of the tunnel in loose soil (up to > 20 m-span) runs through the town center with shallow overburdens, less than 10 m, alongside or directly under numerous buildings. In the rocky part, an underground roundabout with a total diameter of 42 m, consisting of a toroidal cavity with a central rock pillar with a diameter of 8 m, is present. The roundabout connects the ring road to an underground 7-storey car parking, consisting of a cavern, 170 m long, 20 m high and 25 m deep, with shallow vertical and lateral covers.
