ABSTRACT
For the first time in the subways construction practices in the territory of the Russian Federation, a double-track running tunnel was built on two sections of the Saint-Petersburg subway. The drivage carried out by a Tunnel-Boring Machine (TBM) with Earth Pressure Balance (EPB). The tunnels’ route crosses road junctions and railway; buildings and structures are also located in the construction influence zone.
Ensuring the construction safety requires geotechnical monitoring, and one of its goals was adjusting the process parameters of the shield. Adjustment of TBM parameters was made according to the data from borehole extensometers on the tunnel axis at different depths.
The result of geotechnical monitoring, and also the performed analytical and numerical simulations, is conclusion that a major influence on the development of the stress-and-strain state for the tunnels sections passed within the quaternary deposits has the depth of the tunnel and, to a lesser extent, the mechanical characteristics of the soil massif.
