Whilst the furore over the demolition of Plymouth’s “ugly” 1961 Civic Centre rages on (NCE last week), the city is this week preparing to celebrate the opening of a far more worthy icon – the copper-wrapped Roland Levinsky Building at Plymouth University. The £150M nine storey building is designed to be a visible statement of the university’s city centre relocation and its angular geometry, long spans and load transfer structures posed many structural engineering challenges, explains Scott Wilson project manager Jonathan Derwent. Scott Wilson was structural designer for design and build contractor HBG. BDP was executive architect. Split into three structures, the building comprises a reinforced concrete frame on pad foundations, supporting post-tensioned concrete slabs and a steel-framed roof.
The building’s feature roof canopies act in a similar way to a yacht, catching the wind in the sail (canopy) and transferring it through the mast (steel frame) to the hull (concrete frame). Specially fabricated 850mm deep plate girder beams support the extreme wind loads on these “sails”.
Concrete was then chosen for the building frame. Aesthetically it provides the industrial style finishes and unusual floor shapes of BDP’s design concept. Post-tensioned concrete slabs offer the most efficient structural solution for the 10m spans. Being the thinnest and lightest construction available they enabled a reduction in the building height as well as reducing concrete quantities and foundation sizes.
Loads are transferred over the lecture theatres through 1.25m deep, 18m span post-tensioned concrete beams usually used in motorway bridge construction. These key structural elements are designed to resist severe loads and guard against disproportionate collapse. “Walking columns” set at varying distances from the perimeter of the building, create the appearance of the floating copper wrap over the ground-floor curtain walling.
A pair of reinforced concrete cores stabilise the tower. These elements were carefully analysed using finite element analysis in order to fully coordinate with circulation stairs, lifts and service risers.
Value engineering was key to the design process, and while few savings could be found in the efficient building structure, it was adapted to include a series of seminar spaces underneath the ski-slope roof, which improved the gross/net floor area ratio and helped to prop the roof structure and reduce steel beam sizes.