Excavation reaches 66% on longest Bulgarian road tunnel

Located on the Struma motorway, the US$111m project will become the country’s longest road tunnel and is being constructed using the New Austrian Tunnelling Method (NATM).

In both tubes, excavation is progressing in simultaneous advances from north and south ends of around 1.5-2m/day. It is followed immediately by primary lining installation using rockbolts, sprayed concrete and anchors. From the tunnel’s south end, 790m of primary lining has been installed in the left tube, and 706m in the right tube. From the north end, primary lining installation has reached 670m in the left tube and 680m in the right tube.

Construction began in October 2019 last year with sites operating on a 24/7 basis. The GP Group (48%), Global Construction (48%) and Via Plan (2%) Joint Venture is building the project for Bulgaria’s Road Infrastructure Agency (RIA). Finance for the scheme has come from the EU Cohesion Fund and the Bulgarian government.