Extension of the BR 101 Motorway: DSI Rock Bolts stabilize the Formigão Tunnel

A new road tunnel was recently opened in southern Brazil near Tubarão, a town that is located near the Atlantic coast. The Formigão Tunnel is the last of four new tunnels built during the widening of the BR 101 Motorway.

At km 338 of the road widening project, the tunnel leads through Formigão Hill, thus doubling the capacity of the BR 101 motorway. With a total length of 900m, the section included the construction of a 530m long double tube tunnel as well as a 210m long northern and a 160m long southern access road. Both tunnel tubes accommodate two lanes and a pedestrian walkway.

The tunnels were driven using the drill- and blast method at an average advance rate of 4-5m per day.

To stabilize the tunnels during excavation, DSI Underground Brasil supplied 4m long DSI Rock Bolts that were tightly anchored in the load-bearing rock using resin cartridges. Additionally, DSI employees carried out comprehensive performance and pull tests and supported the joint venture with their technical know-how.

Thanks to the excellent co-operation of all companies involved, tunnel advancement was efficiently completed within a short time period.