Crossrail project: use of sprayed concrete tunnel linings on London’s Elizabeth line

Abstract

This paper discusses the use of sprayed concrete linings on the Crossrail project to deliver the Elizabeth east–west railway line across London. It describes how sprayed concrete linings have been successfully used, leading to significant programme and cost savings to the project. Sprayed concrete linings have been used to form complex station tunnel geometries, including tunnel junctions and tunnels of varying cross-section as well as a number of large cross-over caverns, shafts and adits. The design of sprayed concrete lining tunnels is discussed in detail, including how the tunnels were analysed, sized and reinforced to resist applied ground loads. The paper also describes how the technique has been successfully adopted to form the complex caverns at Whitechapel and Stepney Green cross-overs. Topics covered include construction methodology, material selection, monitoring requirements and lessons learnt for application on future projects.