UCLH Proton Unit Case Study
Client: Bouygues UK
Location: UCLH, London
In the development of a high energy Proton Beam Therapy (PBT) Unit for Cancer care in London. The works involve the redevelopment of the Rosenheim building and former Tottenham Court Road Odeon site adjacent to UCLH, Grafton Way, in London.
The excavation was considered the largest ever undertaken in London in terms of size and depth. With dewatering required for the excavation of multi-level irregular shaped basement with a ~ 300m perimeter. Works were undertaken within a diaphragm wall toeing into the Lower Reading Formation Clay with an excavation level up to 26m BGL.
Stuart Wells had early involvement in the project which began with a conceptual model and design risk assessments that was developed through the process of installing piezometers to establish groundwater level in the various soil formations.
A dewatering design was established using numerical modelling software SEEP/W. Further to which a dewatering system was installed that consisted of 8no internal dewatering wells targeting sand layers within the Lambeth Beds. Internal and external groundwater levels were monitored throughout the period. Dewatering wells were reduced as excavation progressed. Through a process of monthly design assessments using flow, water level and rising head data. Initially the wells were pumped from and then bthrough the project the number of active pumping wells was reduced and the system adjusted to a passive pressure relief system.