St. Petersburg Metro. Line 1

— Project Description:

The section between Lesnaya and Pl. Muzhestvava stations crosses the middle of a buried paleo-channel, filled with water satured bearing soft soils with very poor geotechnical properties, in an urban environment. The excavation of this stretch was driven with a hydroshield TBM to deliver the necessary pressure for face stability against groundwater pressure up to 6 bars. The TBM parts were transported at tunnel level through a 70m-deep shaft and then mounted in an assembly chamber, previously excavated by conventional method (SEM) starting from Lesnaya. After excavation of the first tunnel, the machine was reversed inside a returning chamber (this time excavated from Pl. Muzhestva) for the excavation of the second tunnel.

— Description of Services:

Feasibility Study and Preliminary Design to the Contractor (Impregilo-NCC) during the tender phase; Assistance on site during additional site investigations; Detailed Design of the tunnels; Detailed Design of pre-cast lining; Excavation operational procedures set up; risk analysis and risk management plan during construction; Assistance and expertise to the Contractor during construction.