As part of the redevelopment of Tottenham Court Road, the existing London Underground ticket hall will be extended beneath Charing Cross Road.
When complete, the ticket hall will be nearly six times the current size offering new dramatic entrances to the station outside Centre Point and Oxford Street, with lift and escalator access from the ground to platform level to both Northern and Central lines and the new Crossrail station platforms.
Crossrail has started constructing the new western ticket hall 250m west of the current station entrance on Dean Street. This western entrance to the station will be located on Dean Street and will provide step free access to the Crossrail platforms.
Crossrail and London Underground have had to overcome a number of challenging issues to construct this new station in what is a heavily built up environment containing many historical structures which make Soho the attractive place it is to live and work. The worksites are also next to one of the major shopping and business areas in the world and Crossrail and London Underground are working with many organisations to ensure the safety of the public as well as managing the pedestrian, public traffic and construction traffic routes around the sites.
In addition, Crossrail and London Underground have the added challenge of building this new infrastructure very close to a number of existing tube lines and ensuring that these major commuter lines can contiune to operate while the work is undertaken.
A primary engineering consideration is to monitor and manage the vertical and lateral ground settlement of the area around the new station so that the integrity of the buildings under which the station is being constructed is maintained. Below the ground the project engineers have taken into consideration the nature of existing building foundations and their relationship to the new tunnels and ticket halls.
The two tunnel boring machines being launched at Royal Oak in 2012 to construct the running tunnels to Farringdon are currently scheduled to reach the Tottenham Court Road area in early 2013. Once the tunnel boring machines have passed through the station, the tunnels will be enlarged to create enough space for the new platforms and interconnecting passages.
Progress and next steps:
London Underground and Crossrail are working closely to deliver the station’s transformation. Work on the eastern ticket hall is already well under way. London Underground's contractor, Vinci BAM Nuttall JV, has completed the piling for a new Northern Line escalator box and Charing Cross Road has now been diverted around the back of Centre Point to create a worksite large enough to construct the new ticket hall under Charing Cross Road.
Adjacent to the Northern Line tunnels and Charing Cross Road, the new escalator shaft is nearly 30m-deep and will provide a much needed additional access to the Northern Line.
Work to replace the extensive utilities beneath Oxford Street was completed in November 2010 ahead of schedule. Some of the utilites dated back to the early 1800s and it was vital to replace or strengthen each major utility prior to tunnelling works.
During June and July 2011, 11 large plunge columns were constructed at Tottenham Court Road. The largest piling rig operating in Europe was used in the project to sink the deepest piles ever constructed in the UK. The columns will eventually support a new private development above the station, on the west side of Charing Cross Road.
For Crossrail's western ticket hall, all the buildings required have been succesfully demolished in the area bounded by Dean Street, Diadem Court, Great Chapel Street and Oxford Street. Balfour Beatty Morgan Vinci Joint Venture (BBMV) has been appointed as the contractor to build the station box for the western ticket hall and has commenced the piling operations. BBMV have constructed 39 bored piles on site to support the station and the private development above. They are also well under way with the construction of the ticket hall box structure using a method called diapgragm wall piling.
The station platform tunnels will be bored out by tunnel boring machine (TBM). The two TBMs for the western drive will be launched from Royal Oak in Spring 2012. The two TBMs are likely to reach the Tottenham Court Road area by late 2012/early 2013.
London Underground's station upgrade is expected to be completed in 2016. Crossrail services are expected to start operating in 2018.
Balfour Ferrovial Keir Joint Venture (BFK) have started utility diversions in Soho Square to facilitate the construction of four grout shaft in the roadways. Compensation Grout Shafts are used to protect buildings from the potential effects of ground settlement during tunnelling. BFK held an exhibition in Soho Square on 18 August 2011 to explain the works that will be undertaken for the grout shafts. The exhibition panels can be downloaded here: Download Soho Square Grout Shaft Exhibition August 2011
Utility works for the grout shaft in Sheraton Street has been completed and the shaft is currently under construction with a sixth shaft planned in Goslett Yard in due course.