The City of Buenos Aires, Argentina, is expanding it’s metro network. Some 13 km of new tunnels have been excavated since 1998 and some 20 km are scheduled for construction in the near future. Many major improvements have been implemmented during these years in the fields of design and construc- tion procedures. Some of the achievements and lessons learned are described in this paper, including: charac- terization of Buenos Aires soils for the numerical modeling of NATM tunneling, description of the design and construction procedures in use and some comments on the observed ground behavior during construction.
