Cantareira Consortium Completes Opening of Tunnel 101 on the Northern Rodoanel

Tunnel 101 is a twin tunnel composed of two lanes. The inner lane is 1,088 meters long and already open, while the outer lane—whose excavation has now been completed—measures 1,070 meters. The structure crosses a geologically complex massif, with stretches of soil, mixed sections, and significant water presence. Resuming the excavation required highly controlled rock blasting, meticulous planning, and continuous technical monitoring.

At the peak of operations, around 300 workers were directly involved in excavation and associated services. Throughout the construction, approximately 32,000 cubic meters of material—soil and rock—were removed.

Excavation is being carried out using the NATM (New Austrian Tunneling Method), employing lattice girders and shotcrete with macrofibers, a technique that provides greater stability to the massif and increased safety for the teams.

All excavation progress was monitored 24 hours a day, with geotechnical instrumentation control and strategically positioned seismographs, ensuring that the vibrations generated by blasting remained within the limits established by environmental legislation and technical standards.

In addition to engineering challenges, the project demanded continuous attention to the relationship with the surrounding community due to its proximity to residential areas. Ongoing dialogue and mitigation actions were essential to maintaining a positive relationship with residents throughout the execution.

With the completion of the excavation, Tunnel 101 will move on to the next stages, which include lowering the floor to reach the final geometry, construction of the secondary lining, paving, installation of duct banks, emergency tunnels, and implementation of signaling and safety systems.

Section 2 of the Northern Rodoanel is 35% complete. Once finished, it will connect the Fernão Dias Highway to Avenida Pereira de Magalhães. Initial activities to resume tunnel excavation began in April 2025, after more than seven years of interruption. The excavation of the outer lane began on June 16, 2025, requiring a series of preliminary treatments and technical interventions to ensure safety, stability, and quality in the execution.