Civil and structural engineering design for the Elizabeth line station at Tottenham Court Road

The new Elizabeth line station at Tottenham Court Road, delivered by the Crossrail programme, has been an exercise in interface management as well as a feat of engineering. This paper describes the design carried out by the Arup Atkins Joint Venture (AAJV) under contract C134, principally of the Western Ticket Hall box. Nestled in Soho, this was developed within a dense urban grid and the constraints of a residential oversite development above. The team worked closely with London Underground Ltd's engineers at the Eastern Entrance, which was delivered as part of London Underground’s own station upgrade works. The tunnel for the eastbound Elizabeth line passes through the Western Ticket Hall box, which also provided construction access for the sprayed concrete-lined platform and concourse tunnels. Access dates to the site meant that there was insufficient time to complete construction of the box before the arrival of the tunnel boring machine (TBM). Consequently, the need to complete the excavation became critical and the team adopted a bottom-up construction sequence for one of the deepest open shafts ever excavated in central London. The box, formed of elements of diaphragm walls and raft, was constructed before the TBM arrived, and the remaining internal elements completed afterwards.