ABSTRACT
The development of Earl’s Court Village, London, begun with the demolition of Earl’s Court 1 (EC1) and Earl’s Court 2 (EC2) exhibition centres, directly above London Underground Limited (LUL) running tunnels. Excavations as close as 150 mm above a brick arch running tunnel were required in order to remove deep transfer beams buried below the basement slab. Numerical modelling of the shallow cut-and-cover brick arch tunnel was undertaken to understand the stress change within and displacement of the tunnel lining. Acceptability criteria were agreed with the asset owner, LUL, and compared with the finite element model results. The excavation profile was adapted to provide sufficient confining stresses during each construction stage. Automated in-tunnel monitoring and a condition survey, including hammer tap testing, was used to validate the modelling parameters adopted. This case study sets out a holistic risk assessment approach incorporating numerical modelling and compares monitoring data to calculated movements in order to appraise brick arch tunnel modelling parameters and provide a precedent for future assessments of brick arch tunnels.
