London Underground Monitoring | Murphy Geospatial
Services (Technical Disciplines)
The task of reconstructing John Nash’s Regent’s Crescent without damaging it’s Grade 1 listed façade or the Jubilee Line tunnels running just below presented many challenges. Management of those challenges was achieved, in part, through insight from a unique monitoring programme built around Senceive remote monitoring technology in the hands of experts from Murphy Geospatial. The bespoke solution enabled ground risk and impact on third parties to be measured and managed in a way that was safe, cost-effective and reliable.
Built in 1820, Regent’s Crescent is a prime example of Regency architecture and proposals to demolish and re-build the mixture of properties behind its iconic facade to deliver 83 high-end apartments required a robust monitoring plan. With the redevelopment including excavation of a full-footprint basement, safeguarding the tube tunnels was a fundamental part of that plan.
Established methods to monitor convergence and divergence in the tunnels including manual measurement and automated total stations were rejected because of drawbacks including the need for frequent access, power supply, extensive cabling and cost.
A total of 250 tilt nodes were installed in sets of five around the tunnel intrados, providing geographically remote stakeholders with virtually realtime insight into movement within the zone of influence. By establishing that the magnitude of movement caused by the construction activity above the tunnels was within predicted safe levels the monitoring helped to keep the construction programme on track and to satisfy third parties including London Underground and other property owners that their assets were not under threat.
Project Objectives/ Outcomes
The installation and monitoring of the tunnels took place over 5 years approximately. With the completion of Regent’s Crescent development last year in 2020. Murphy Geospatial delivered final monitoring reports to London Underground prior to removing the kit in 2020. Ongoing analysis of the data continues to get a better understanding on how tunnels of this type behave when put under stress from above.
Monitor movement of London Underground tunnels to reduce costs and risk during the demolition and construction works.
Geoscience Ireland Contact | Andrew Masters, Head of Department – Monitoring, firstname.lastname@example.org