Contractor Carlomagno Gaetano from Lagonegro in northern Italy has been contracted by main contractor SIS to build the new Renazza Tunnel on the A3 Salerno-Reggio Calabria highway. The previous tunnel, which collapsed in the past, is constructed through fragile ground conditions of mainly sand and clay, calling for delicate operations.
Contractor Carlomagno Gaetano from Lagonegro in northern Italy has been contracted by main contractor SIS to build the new Renazza Tunnel on the A3 Salerno-Reggio Calabria highway.
The previous tunnel, which collapsed in the past, is constructed through fragile ground conditions of mainly sand and clay, calling for delicate operations.
Italian-Spanish contractor SIS entrusted Carlomagno with the excavation, and with disposal of the excavated material from the tunnel workings.
The two tunnel bores run parallel to the previous tunnel gallery, presenting several problems for the contractor in the delicate ground conditions.
Leading the way is a Case CX350B crawler excavator with a hydraulic breaker, which advances at a rate of 4m per day.
“Twenty years ago, soon after its opening, the tunnel collapsed,” says manager Nicola Carlomagno. “For this reason the new construction involves long stages of strengthening of the tunnel walls before advancing.”
As the CX350B advances pre-cast reinforced concrete sections forming an arch within the tunnel walls are installed to provide structural strength. Two Case CX230B excavators are used to load material onto trucks, while a 435CT compact tracked loader is used to keep the working area clean.
A short radius CX50 mini excavator with a hydraulic breaker is also being used on the contract to prepare the area where support beams leading to the tunnels will be placed.
Carlomagno originally started in the quarry industry and has moved into public works and infrastructure more recently. The company has experience of the Case machines from its quarry workings, leading to further purchases from supporting dealer Lucana Tractors of Vaglio Lucano.
Within the quarries the company has a CX230B that has amounted 5,164 working hours in just 18 months, along with a Case 821E wheeled loader that offers high productivity and low fuel consumption.
The 700,000m3 of excavated material from the tunnel bores is being transported to the company’s Zanco Quarry near to the project. Here the 821E is being used to reinstate the quarry working and reform the shape of the mountain, which will eventually be covered in chestnut trees typical of the area.
“The idea came after realising the amount of material coming out of the tunnel excavation,” says Carlomagno. “We talked about it with the regional authorities and they liked the idea. The quarry side will come back to its original shape, thanks to the large quantities of earth which will naturally recreate the mountain.”
