Construction of Excavation and Remediation Works

Execution of 10,000 square meters of diaphragm walls, installation of struts and metal braces, and execution of 1,600 meters of anchors.

Construction of the foundation works for the new San Giorgio Viaduct.

Execution of 1500mm diameter piles for piers 1 to 13 and the western abutment, totaling approximately 9,000 meters.

Construction of foundation and consolidation works across various WBS for the extension of the Milan – Venice High-Speed/High-Capacity Railway Line, Brescia East – Verona section.

Key Works Include:

• Jet grouting consolidation for the Lonato tunnel entrances
• Consolidation works for the excavation of the San Giorgio in Salici Natural Tunnel
• Execution of piles for noise barriers
• Construction of diaphragm walls for the artificial tunnel and new Peschiera del Garda interchange
• Jet grouting consolidation for the Madonna del Frassino artificial tunnel
• Execution of bored piles and jet grouting consolidation for the excavation of the piers of the Fiume Chiese viaduct

The restoration project of the bottom outlet of the Pozzillo Dam is a funded initiative under the National Recovery and Resilience Plan (PNRR). This project aims to enhance the safety and efficiency of Sicilian water infrastructures, ensuring a continuous and secure water service for the local community and the agricultural sector that relies on the dam’s water.

Located in the Municipality of Regalbuto, Enna, the dam required urgent interventions to guarantee its long-term functionality and prevent potential risks related to structural damage and excessive sedimentation.

The main planned works include:

Construction of a New Intake
A new intake will be constructed at an elevation of 333 meters above sea level, connecting to the existing discharge tunnel located at 317 meters above sea level. The tunnel will have an overall length of about 40 meters, with an initial section at a slight incline and a second curvilinear and inclined section, with a diameter varying between 5 and 4.3 meters.

Excavation and Installation of the Interception Shaft
A vertical shaft approximately 39 meters deep will be excavated to connect the new discharge to the existing tunnel, allowing for the interception and diversion of the water flow.

Defense Works for the Channelization of the Riverbed
Support structures using O-Pile technology will be constructed to confine the dredged volume.

Removal of Lake Sediments
Sediments accumulated in the area in front of the new intake will be removed to ensure a continuous and unobstructed water flow.

Consolidation of the Downstream Banks
Works will be carried out to consolidate the banks downstream of the dam to prevent erosion and ensure structural stability.

Maintenance and Cleaning of Existing Structures
Extraordinary maintenance will be performed on the lining of the dam’s bottom outlet tunnel and the access shaft to the maneuvering chamber, including the replacement of hydraulic and electrical systems controlling the new gates.

The main specialized activity necessary for the successful completion of the work is the construction of the support structures for the excavation required to intercept the existing discharge tunnel to which the new bottom outlet will be connected.

The implementation of “O-Pile” (interconnected piles) using the Down-The-Hole (DTH) reverse circulation system with sacrificial shoe represents an advanced method for installing large-diameter piles in difficult geotechnical conditions. This technology is particularly suitable for hard or very compact soils where other drilling methods might be ineffective. This system is especially effective in ensuring the stability of deep excavations and protecting work areas from water infiltration and ground settlements.

The “O-Pile” will be partly constructed from land and partly from the water. To accomplish the latter, a modular floating pontoon will be used.

Construction of excavation containment works for the expansion of Teatro alla Scala on Via Verdi.

The intervention includes the installation of a berlin wall with perimeter micropiles, anchored with four orders of anchors, a bottom plug created with cement injections, and metal contrast works. The perimeter berlin wall, given that the excavation is about 4 meters below the water table, has been waterproofed with the creation of a jet grouting barrier.

A total of 7,000 meters of micropiles, 5,000 meters of anchors, and 3,500 cubic meters of soil treated with cement injections have been completed.