Crossrail Farringdon Station - Geotechnical Assessment

Owner
Crossrail Ltd. - TfL
Client
Bam Ferrovial Kier BFK
Cost
£300 million GBP
Timeframe
May 2013 — October 2015
Services performed
Temporary works design included design of tunnels prior to ring closure and 28 day strength as well as depressurisation design.
Description
The station is located in central London between Tottenham Court Road and Liverpool Street Crossrail (CRL) Stations. Constructed in the geologically most complex area in the whole of CRL, an optimised geotechnical and SCL tunnel design was implemented, which resulted in significant time and cost benefits for the project. Using a dynamic 3D geological model in conjunction with SCL tunnelling represented a key element of the geotechnical risk management framework.
Geology
Excavation encountered almost all the London basin units but mainly Lambeth Group, comprising stiff to very stiff overconsolidated clays to water bearing sand units.
Location
London, UK

Highlights

  • SCL tunnels in CRL without pilot tunnel
  • Reduction of in-tunnel probing quantities by 70%
  • Dynamic 3D geological model
Qualitative geotechnical risk mapping

Qualitative geotechnical risk mapping

Exerpt of the 3D finite element model

Exerpt of the 3D finite element model