The project for the construction of the T3 section of the new Rome Metro, Line C, requires the use of the Compensation Grouting technology. Said technology mitigates and compensates for the subsidence basin induced under the footprint of the foundations of the Aurelian Walls, during the excavation and construction of the two Line tunnels with the TBM technology. During the drilling phase, No. 77 TAM (Manchettes tubes) were installed, for a total of approx. 3,950 m of drilling along with approx. 4,450 valves installed on a surface of ca. 2,400 square meters.
drilling works were carried out with the TDDT/HDD technology, which allows the control of the drilling progress and the possible correction during work. The pre-treatment phase of the volume of soil below the footprint of the Aurelian Walls involved the injection of cement mixtures for a total grouted volume of 1,530 cubic meters.
The conditioning phase was characterized by the injection of cement mixtures for a total grouted volume of 300 cubic meters. The compensation phase, during the passage of the two TBM rigs below the foundations of the Aurelian Walls, was successfully completed and the subsidence basin reabsorption is currently being completed. As of today, the volume injected for this last phase amounts to approx. 400 mc.