ABSTRACT
The past decades have shown important progress in the planning and construction of underground works. Tunnel excavation methods have evolved in a similar manner, from systems that used partial section excavation, to full-bore driving with complete control of the rock mass deformation process by limiting the size of the plasticized areas around the cavity and using partial section excavation only in exceptional cases. These technical and technological developments are matched by the difficulty of determining construction costs, as these are linked to the conditions of the rock mass to be excavated and further impacted by logistics, which is an extremely significant issue when dealing with long, deep tunnels. The present report shows the costs resulting from various types of rock mass, comparing them to the cost of excavations.
