In this project, the work package assigned to VINCI Construction Grands Projets includes the rehabilitation of a 30-kilometre motorway segment, including upgrading asphalt paving for 120,000 m2 of road surface, installing vertical and horizontal road signs and safety systems, planting 30,000 shrubs, restoring irrigation systems, and upgrading the lighting system.
The work package also encompasses specific new construction, including erecting 3,600 m2 of operational buildings in proximity to the Leptokaria toll station as well as toll barriers located at a nearby interchange. To the north, it includes the demolition and rebuilding – without disrupting traffic – of a 14,000-m2 bridge and creating 30,000 m2 of landscaping on a slab above a cut-and-cover trench located in the city of Katerini.
We also built a dual-tube motorway tunnel – known as Tunnel T1 – that features two traffic lanes 3.75 metres wide and an emergency lane 2.5 metres wide. Tunnel T1 consists of dual tubes linked by inter-tubes located at 300-metre intervals. The excavation section was quite large, covering over 110 m2 in the open section and up to 180 m2 in closed sections in more challenging geological terrain. Tunnel construction was divided into three major phases: excavation, concrete lining, and electrical and mechanical equipment. We used flexible primary supports and unreinforced concrete to create the lining segments.
As a result of the constraints we encountered, particularly regarding the presence of seismic faults in the valley, we employed a conventional permanent surfacing approach using reinforced concrete.