The Silvertown tunnel project consists on the construction of a tunnel between Greenwich and Silvertown districts (London). The project includes a tunnel construction under the Thames River with of 1.4 km in length and 0.60 km in length of access ramps. The tunnel excavation is delveloped with two tunnel excavation methods: by means of an EPB TBM and with Cut and Cover, the latter used in the tunnel access ramps.

The project includes the construction of the following structures:

  • Cut and Cover North, which corresponds to the Silvertown District access ramp (next to the River Thames).
  • Cut and Cover South, which corresponds to the Greenwich District access ramp.

The project also includes several control shafts construction for the tunnel excavation:

  • Rotation Shaft, a Greenwich’s shaft that connects the Silvertown Tunnel and the Cut and Cover South.
  • Launch Shaft (also known as Peanut Shaft), a Silvertown district’s shaft.
  • Retrieval Shaft, a Silvertown district’s shaft that connects the Launch Shaft with the Cut and Cover North.

PRO GEO has been hired for the geotechnical analysis of the Cut and Cover North, Rotation shaft, Launch shaft and Retrieval shaft.

PRO GEO’s experience has helped solve the following problems:

  • Three-dimensional geomechanical modeling in Midas GTS NX and Plaxis 3D of the Rotation Shaft construction.
  • Three-dimensional geomechanical modeling in MIDAS GTS NX of the Launch and Retrieval Shaft construction.
  • Two-dimensional geomechanical modeling in 2D Plaxis of the Cut and Cover North construction.
  • Horizontal movements estimation of the shaft temporary support.
  • Alternative support study for the Rotation Shaft.
  • Dewatering design for the Rotation Launch and Retrieval Shaft’s construction.
  • Anchors and struts optimization for the Cut and Cover North temporary support.