ABSTRACT
In recent years, conventional excavation, although making way for techniques that guarantee higher levels of safety, has been proved irreplaceable in all cases where logistics or high investment costs do not permit the use of alternative solutions. Therefore, studies and research have been promoted for solutions capable of reducing the risks associated with the activities closest to the excavation face, thus bringing about an evolution in conventional excavation, especially focussing on pre-lining with steel ribs and shotcrete. In this paper, a new methodology will be described. One which will install the rib, with different radius and types using a single operator and without any personnel below the excavation face. The new methodology allows to reduce the time for the rib’s installation and the excavation’s cycle. The initial testing of the “Automatic Rib” system was performed at the impetus of the client Autostrade per l’Italia S.p.A. at the Sappanico tunnel, for the works to widen the A14 motorway, between “Ancona nord and Ancona sud”. Works were directed by Spea Ingegneria Europea and carried out by Ghella S.p.A.
