Bank Station Capacity Upgrade - Impact Assessment

Owner
Immersed Tube
Client
Dragados S.A.
Cost
£563.8 million GBP
Timeframe
January 2013 — May 2019
Services performed
Assessment of the impact on existing cast-iron and precast concrete tunnel linings (in total approximately 300 assets.) including empirical and finite element calculations.
Description
Bank Station is a London Underground station located in the City of London financial district. It is a key interchange served by five existing lines. The Bank Station Capacity Upgrade (BSCU) comprises the construction of new tunnels adjacent to and connecting with the existing tunnels. A staged, risk-based approach was used to efficiently assess the affected existing assets and determine an appropriate mitigation and monitoring scheme. Empirical methods and complex numerical models were used at the different stages of the assessment, to understand the risk to the existing railway and how they could best be managed while minimizing disruption to the station and its users.
Geology
The geology comprises London Clay formation overlain by Quaternary superficial deposits comprising river terrace deposits and alluvium which are generally overlain by made ground.
Location
Cut & Cover

Highlights

  • ASSESSMENT OF 100 YR OLD CAST IRON TUNNEL LININGS
  • condition/intrusive surveys and inspections
  • staged risk-based analysis to focus complex modelling on critical assets

Existing escalator at Bank Station

FE model of existing (green) and new (red and pink) structures