Seal of approval

Alterations to a building located between London Wall and Finsbury Circus and right over a new escalator tunnel to Liverpool Street Crossrail station would cause loading changes not taken into account in Crossrail's design. Therefore planning approval required Crossrail's acceptance that the proposed changes would not exceed the very tight tolerances on escalator tunnel distortion and twisting.

A 3D FEA model of the building sub-structure, proposed changes and underlying ground around the escalator tunnel was used to predict that the tolerances would be satisfied and help gain planning approval.

Highlights

• Study of detailed site investigation data for Crossrail station.

• 3D FEA model with advanced non-linear soil models for improved ground movement predictions.

• Simulation of existing building and proposed remodelling.

• Prediction of displacement, distortion and twisting of escalator tunnel.

• Acceptance of predictions leading to planning approval.