Hard rock that has to be adapted to a complex infrastructure. A hydraulic breaker designed to solve the toughest problems. Two rivals in a fascinating contest, and the latest technology from Apulia looks set to win the day.
"A key project in the reliability check which our infrastructure system has simply got to pass". That could be a good way of summarising the Variante di Valico. A fundamental project for traffic flows in Italy, currently being carried out on the A1 motorway, on the stretch of Apennines between Sasso Marconi and Barberino del Mugello. 62.5 km of improvements to traffic flow, cutting journey times between Bologna and Florence.
We went to the site to see some of the equipment being used, in particular the Indeco HP 7000hydraulic breaker, one of the most advanced pieces of "heavy" equipment. For several months, two of them have been very successfully used in the two shafts being dug at the Galleria Largnano tunnel, between Aglio and Barberino del Mugello.
4 million travel hours a year, 90,000 vehicles a day, with peaks of 24,000 journeys by lorries or coaches – data which underline the inability of Italy's current A1 motorway, especially around the critical area between Sasso Marconi and Barberino.
The improvements currently being carried out by the motorway management firm, Autostrade per l'Italia involve widening the motorway to three lanes in each direction, building a new motorway, known as the Variante, to ease the pressure on the existing one, and creating a new three-lane stretch of motorway for traffic heading south, and finally rebuilding the Barberino exit from new plans.
The works are taking place in eight different municipalities in Emilia and in Romagna and the total cost of the operations runs to around 3.1 billion euros. By the end of the project, 23 viaducts and 23 tunnels will have been built. There are over 5000 people working for the construction firms, with hundreds of machines for roadbuilding, for foundations, for excavations and for transporting and disposing of rubble.
The Baldassini Tognozzi Pontello firm started work on site in September 2006. They have currently managed to tunnel 118 m into the southern shaft and 94 m into the northern one. Both shafts are equipped with two excavators, each mounted with a hydraulic breaker.
Current progress amounts to 3-4 metres a day for the two shafts: "Apennine rock is very variable", explains the surveyor, Giorgio Ivol. "In the southern shaft, for example, up until about three frames ago, the biggest problems we had were with hardness. At the moment we're moving ahead quite smoothly there, with good productivity, but we're now having similar hardness problems in the northern shaft".
Their New Holland E485 50-ton tracked excavator is mounted with an Indeco HP 7000 with an operating weight of 4000 kg. It is particularly well-suited for such a tough job, as it can apply pressure of 140-150 bars at a power of 76 kW. "The reason for choosing the two Indeco breakers for the excavators working in the two shafts was because the work is non-stop", said Ivol. "So reliability and productivity need to be as high as possible, on a job that will be going on for at least a year."