Campbell Reith and contractor ESG have started work on a challenging ground investigation for a new Proton Beam Therapy (PBT) facility for University College London Hospitals NHS Foundation Trust (UCLH) in London.
The investigation has had to overcome a number of access challenges associated with working in the basement of an active hospital, resulting in the use of a cut down rig and hand held tools for pitting and window sampling.
A desk study of the site also revealed that the site lies close to a fault, potentially resulting in the Lambeth Group being comparatively shallow and historic investigations indicated the potential for significant hydrostatic pressures. The site is particularly sensitive to ground movements given the proximity of nearby residential structures and London Underground tunnels.
Works include rotary drilling to obtain Category 1 samples for anisotropically consolidated small strain stiffness tests to allow the assessment of horizontal movements resulting from basement excavation, and oedometer tests to assess soil heave and consolidation. Piezometers have been installed to fully characterise the pore pressure profile and waste classification testing will enable the significant volume of arisings to be disposed of sustainably and efficiently.
The investigation will enable foundation assessments and modelling of vertical and horizontal ground movements to be carried out by Campbell Reith for the three to four floor facility that is likely to be up to 25m below ground level.
The contract at UCLH is the second PBT project that Campbell Reith has been awarded in recent months with the company also commissioned to undertake a similar project for the Christie Hospital in Manchester.