The Consorcio Constructor Metro 2 Lima (CCM2L), formed by the companies Salini-Impregilo, Dragados, FCC and COSAPI, responsible for the construction of Line 2 and the Faucett Avenue - Gambetta Avenue branch line (future Line 4) of the Basic Network of the Lima and Callao Metro, which will connect the districts of Ate and Callao, from the east to the west of the Peruvian capital, has commissioned Lombardi to provide on-site technical assistance for the excavation monitoring of the 2 TBMS used for the materialization of the tunnels.
The project, with a total investment of more than US$ 5.6 billion, comprises a total tunnel length of 34.5 km, of which 26.5 km correspond to Line 2, with a total of 27 stations, and 8 km correspond to the Line 4 branch, with a total of 8 stations.
The TBMs, 10.20 m in diameter, work in a Lima gravel soil (GP-Sf) with a grain-supported structure and the presence of boulders, which makes soil conditioning and special treatments necessary to ensure safe progress, protecting the equipment and existing infrastructure on the surface.
To meet these objectives, Lombardi has developed the analysis and verification of the stability and pressure in the excavation face, the definition of the modes of operation with working pressures of the TBMs in the entire longitudinal and geotechnical profile of the tunnel, the definition of the safe points for the revisions of the cutting head, the analysis of the entrances and exits of all the stations and zenith shafts, the monitoring and analysis of the excavation in both TBMs during the whole operation, the study of materials in the laboratory, the intervention project of soil consolidation and treatment for the TBM start-up and the development of special interventions to secure the TBMs in their crossing with important interferences.
