London Underground: Wellgarth Road

Fluid have been involved in several projects where it has been necessary to negotiate with London Underground to construct new buildings or alter existing buildings above or adjacent to existing LUL tunnels.

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The project involved the conversion of an existing five storey hostel building to high quality apartments and the construction of two new 4 storey detached high quality houses on a site in Golders Green. The Northbound and Southbound Northern line tunnels run beneath the site and as a result it was necessary to isolate the structures from the foundations on elastomeric bearing pads to ensure that structure borne noise and vibration were reduced to negligible levels.  It was necessary to agree demolition and new structural proposals with London Underground.


  • The buildings and tower crane were supported on piled foundations. If the location of the tunnels had not been properly determined piles could have been installed through the crown of the tunnel.
  • Construction traffic could have caused damage to the tunnels if the loads were too close or too large.
  • Excavations too close to the tunnels could have damaged the tunnels or allowed excessive water ingress.

Design Procedures

  • Contacted LUL at an early stage in the project before any design work had commenced.
  • Established the location of the tunnels and produced drawings to show the relationship between the buildings and Northern Line tunnels.
  • Vibration measurements were taken on the site to establish how vibrations from the trains in the tunnels would affect the foundations. Based on this a decision was taken to isolate the foundations.
  • Once the scheme was sufficiently developed an Approval In Principle (AIP) submission was sent to LUL for their approval.
  • When the AIP was approved by LUL work commenced on site.