Geotechnical aspects of the Jubilee Line Extension, London

This paper describes the geological setting, the ground investigation, construction methods and geotechnical processes used on the Jubilee Line Extension to the London Underground railway network. In particular, it describes the performance of earth pressure balance and bentonite tunnelling machines in the mixed ground conditions of south east London, the methods of predicting and dealing with settlement caused by tunnelling and some geotechnical problems experienced during the project.