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.

Advanced design of large cavern intersections in soft ground without conventional bar reinforcement

“…The Abaqus Concrete Damaged Plasticity (CDP) model [3,4] is capable of capturing this behaviour, yet being rather simple in regards to both input parameters and ease of interpretation. CDP assumes tensile cracking and compressive crushing mechanisms with the uniaxial compressive and tensile response characterized by damaged plasticity as shown in Figure 1.…”

Simulating composite behaviour in SCL tunnels with sprayed waterproofing membrane interface: A state-of-the-art review

“…Due to lack of confidence in the membrane interface properties and the membrane's ability to transmit the required shear, particularly when "wet", the composite shell option has not yet been assumed in design [3,5,41]. One of the main aims of this paper is to provide guidance on analysis and on the effect of variation in membrane mechanical properties due to for example creep and water saturation,…”

“…Although a great advance in SCL tunnel design, lack of knowledge on composite structural action meant that Crossrail in their engineering standard [45] specified no tension and full slip in shear should be assumed at the membrane interface in numerical modelling. This was based on the limited knowledge by that time, namely that interface tension and shear (if they exist) are both be beneficial to the tunnel and ignoring them generate a conservative Su & Bloodworth: Simulating composite behaviour in SCL tunnels with sprayed waterproofing membrane interface: a state-of-the-art review design [41]. Therefore, the composite SCL tunnel was essentially designed as an unbonded double shell.…”

Damage Evolution of Steel Fibre-Reinforced High-Performance Concrete in Low-Cycle Flexural Fatigue: Numerical Modeling and Experimental Validation

“…Therefore, steel fibre-reinforced concrete has been applied in several areas. For example, in precast segments for tunnel linings, e.g., for the Brightwater tunnels or the Crossrail project in London [ 3 , 4 , 5 ]. Meanwhile, a state-of-the-art report for using steel fibres in precast tunnel segments has been published [ 6 ].…”