“TREVI-CALATORE”: AN INNOVATIVE SYSTEM FOR THE INSTALLATION OF STRUCTURAL COLUMNS IN TOP-DOWN EXCAVATION AND TUNNELING-Paper

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The paper presents the “TREVI-CALATORE,” a system developed to install heavy plunge columns accurately within bored piles for top-down underground construction. It was used at Florence’s new Belfiore high-speed railway station, where the project required 250 steel columns—each weighing up to 20 tonnes and extending roughly 22–25 metres into piles 50–70 metres deep.<br /><br />The system uses two relatively lightweight frames. A base frame is fixed to the pile’s steel casing, while an upper leveling frame is adjusted horizontally using screw bars and topographic controls. The column is then lowered into position and its inclination fine-tuned with screw jacks, with an inclinometer providing real-time monitoring. Because the column itself does not need to be moved to achieve plan alignment, the equipment can be lighter and easier to handle than conventional heavy positioning platforms. Adjustments are accessible above ground, and column alignment can be controlled independently of the bored pile’s verticality.<br /><br />The installation process includes casing and pile construction, placement of the reinforcement cage, frame alignment, column positioning, concrete placement, and removal of the equipment after curing. The column is temporarily secured to the casing while the remaining bore is backfilled.<br /><br />The system successfully installed all 250 plunge columns within the required design tolerances and schedule. The authors conclude that it is suitable for similar top-down projects requiring precise placement of structural columns within deep foundations.

Keywords

TREVI-CALATORE

plunge columns

bored piles

top-down construction

column alignment

deep foundations

Florence Belfiore station

steel columns

inclinometer monitoring

foundation installation