This building is one of the first of its kind in the UK and will form part of a new national high energy proton beam therapy programme run by the NHS. Proton beam therapy is a highly targeted form of radio therapy capable of treating tumours in hard-to-reach areas, with the potential to minimise damage to nearby tissue and other side effects.

The facility consists of a six storey 220,000ft² Oncology and Haematology centre, providing inpatient treatment facilities, including 7 operating theatres. A Proton Beam Therapy Centre of 80,000ft² arranged over five levels is located below ground (to a maximum depth 28.5m). Above ground, a structural grid of 9m x 9m was adopted, resulting from structural efficiency versus cost optimisation combined with clinical space planning. Structureborne vibration was a key design criteria. Early in the process a range of options were presented by CampbellReith.

The solution adopted utilises deeper slabs than would be required if governed by deflection and strength alone. This has provided full flexibility throughout the entire facility, enabling vibration sensitive equipment to be relocated at any time in the future.

In the proton beam therapy areas, radiation shielding has presented unique challenges. This is achieved using a combination of reinforced concrete walls and slabs up to 4.0m thick, supplemented with dense shielding blocks and steel plates in areas subject to high levels of radiation losses.

In addition to providing structural engineering design services, CampbellReith’s team of specialist in-house geotechnical engineers, environmental scientists and infrastructure engineers form an integral part of our project team, delivering both specific project services and providing additional advice to our structural engineers to enable the formulation of the optimum building solution.

The choice of construction sequences the retaining wall forms was predicated on achieving a solution which could limit lateral deflections and ground movements in both the temporary and permanent conditions, in order not to adversely affect surrounding third-party assets. From the earliest stages CampbellReith collaborated with Bouygues UK to undertake extensive ground modelling.

A full non-linear finite element analysis was undertaken, utilising various retaining wall forms and modelling the complete basement and adjacent structures and infrastructure. As a result, a 1.0m thick diaphragm wall was adopted, which offered the benefit of stiffness combined with improved water tightness.