One of several Crossrail projects entrusted to WJ Groundwater, Farringdon Station sits at the heart of London’s transport system and will provide access to three rail networks: Crossrail, London Underground and Network Rail.
Farringdon will directly connect with three of London’s five airports, providing a highly desirable railway connection between Heathrow and Gatwick.
As we arrived on site, the station was already an interchange for three busy underground lines plus Thames Link. The construction of a major new station for Crossrail below this hub never looked straightforward. This was especially so since the station horizon is within the Lambeth Group stratum. Buut that’s why Crossrail came to WJ – we relished the challenge!
Our initial survey and design analysis indicated that the geological horizon is predominantly cohesive clay, but includes intermittent sand horizons and channels, which may be water bearing. WJ’s solution was in-tunnel probe drilling and depressurisation using vacuum wellpoints or passive relief wells. This avoided the need for surface access, which was highly constrained by railways, Smithfield Market, shops/offices and the compensation grouting tube array. One of the key features of our approach was that the probe holes could be completed as wellpoints once a water bearing sand horizon was identified. This minimised disruption while maximising efficiency through ingenuity.
When complete, it is planned that over 140 trains per hour will flow through the Farringdon interchange when it becomes a link between Thameslink, Crossrail and London Underground services. Farringdon will be the only station from which passengers will be able to access all three networks. In a small way, thanks to WJ’s unobtrusive solutions, Farringdon will become one of Britain’s busiest train stations, and will be a key link in bringing passengers from outer London to the business hubs in the City and Canary Wharf.
- LOCATION: Farringdon, London
- CLIENT: Crossrail
- MAIN CONTRACTOR: BFK (BAM Nuttall, Ferovial, Kier)