Tunnels for Large Crossings: Challenges and Innovations

The paper presents three innovative and cost-effective concepts for the construction of tunnels using the TBM (“Tunnel Boring Machine”) technique: the TISB concept for tunnels built in soft soil, in seismic areas; the TMG concept for railway tunnels, in which a single tube tunnel provides the capabilities usually obtained with two or three tubes; and the TMF concept for roadway tunnels, in which a single tube tunnel provides the capabilities usually obtained with two parallel tunnels. The added-value that can be obtained with the use of these concepts in the construction of tunnels for large crossings is emphasized.