Construction impacts of Crossrail Liverpool Street Station on the Royal Mail Tunnel

摘要

The Crossrail Liverpool Street Station in London has recently been constructed in close proximity to the Royal Mail tunnel. The Crossrail works that have affected the cast iron Royal Mail tunnel include construction of a sprayed concrete lined access shaft within 2m of the tunnel and construction of an 1 lm diameter platform tunnel parallel and within lm beneath the tunnel. Given the very close proximity of the works to the tunnel, this particular interface represented a high risk area of construction. This paper describes how the impact of the Crossrail works on the Royal Mail tunnel was assessed prior to construction. As a result of the impact assessment, mitigation and monitoring measures were proposed. The paper describes the results of the monitoring to assess deformations in the Royal Mail tunnel and provides associated observations of the change of condition of the tunnel.