The Crossrail station at Liverpool Street, London required the downward construction of a 37 m long by 6 m diameter inclined ventilation tunnel using sprayed concrete lining (SCL) techniques. The tunnel penetrated into water bearing channel sands present in the Lambeth Group below the London Clay. This paper describes the development and implementation of an inclined sub-surface ejector well scheme which was used to target and depressurise the channel sands. Access constraints meant that some of the wells were installed from the face part way along the tunnel. The face was enlarged locally to facilitate well installation.
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