'TREVI-CALATORE': INNOVATION IN CUT AND COVER AND TUNNELING FOR THE INSTALLATION OF PLUNGE COLUMNS AIMED TO EXCAVATE UNDERGROUND STRUCTURES THROUGH THE TOP-DOWN METHOD

摘要

The installation of foundation elements (large-diameter Bored Piles or Diaphragm Walls) for the execution of underground works to be performed through the 'Top Down' Technique (Stations, Car Parks, Subways, Artificial Tunnels) often requires the insertion, with pinpoint accuracy, of steel or prefabricated elements within the foundation system, to provide temporary and/or permanent support to the whole structure. The future high-speed railway station of Florence Belfiore (Italy) is a perfect example; the new station will be built in the Northwest area of Florence, about two kilometers far from the existing station of Santa Maria Novella. The project envisages installation of about 500 bored piles (1200-1500-2100 mm diameter), with lengths ranging between 50 and 70 m. In the upper inner part of 250 piles, a steel pipe (weight: 15-20 tons, length: 22-25 mt.) has to be inserted with pinpoint accuracy. The 'TREVI-CALATORE' system allows to install the plunge columns and adjust their position and verticality.