OHL, through its participation in Sociedad Constructora Vespucio Oriente, has reached one of the most representative milestones of the Americo Vespucio Oriente (AVO) urban highway project, the breakthrough of the Pyramid Tunnel, completing the excavation in the progress phase of the 2,025 m that make up the tunnel.

This road infrastructure project will extend over 9.1 kilometers (km) and was awarded by Sociedad Concesionaria AVO I. It is considered one of the largest infrastructure projects in Chile and one of the largest OHL initiatives carried out to date in the country. A team of 3,200 people participate in the consortium that is executing the project.

The tunnel has been carried out under the San Cristobal Hill in the east of Santiago de Chile, linking the districts of Huechuraba and Vitacura, passing under the Mapocho River and the Costanera Norte highway. The works have been carried using the NATM method, with mixed drilling, mechanical and blasting, and coverages ranging from a maximum of 150 m to a minimum of 20 m in the phase under the river and with variable sections between 65 and 170 m2, all of it associated with a slope of 3.5% in almost the entire route.

The main peculiarity of this section of the project is its bifurcation cavern for the Mapocho Branch, which, with a width of 29 m and a total excavation section of 254 m2, is one of the largest of its kind in the world.

The tunnel is designed for three tracks in one direction and a pedestrian lower gallery for evacuation connected to the pressurized emergency exits. More than 200 professionals have participated in the works in triple shifts.