The Agua Negra tunnel is the main component of the "Bioceanic Corridor", an international project aimed to set an efficient roadway crossing through the Andes Cordillera, connecting Porto Coquimbo (Chile) to Porto Alegre (Brazil).
The project includes the construction of a 13.9 km long twin tunnel, linking the two portals at 4'080 m a.s.l. (Argentina) and 3'605 m a.s.l. (Chile). The tunnel is provided with cross passages every 250 m, two ventilation caverns (one provided with a vertical ventilation shaft of 500 m, the other with a 4.5 km long ventilation tunnel). The project includes also the ramps and the control building. The cross section is horse-shoe shaped and the carriage way is two lane wide, with a free section 7.50 m wide and 4.80 m high. There are walk ways on both sides. According to the concept for a longitudinal ventilation, the tunnel is not provided with an intermediate slab.
The construction concept is to excavate the tunnel from both portals, with two contemporary and independent excavation faces each. The excavation will be drill & blast in order to assure the maximum adaptability to the geological conditions.
Particular aspects of the project are the high elevation of the portals, the distance to the nearest urban center (>200 km), the extreme meteorological conditions in terms of wind and thermal excursion and the high seismic risk.
Lombardi is responsible of the new conceptual study, the preliminary project and the technical tender documentations for the underground and external civil works as well as for the electromechanical equipment.