The new Sainsbury Gallery is situated in a 15m deep basement on a site bounded by Grade I and II* listed buildings with unusual and fragile facades. Artifacts sensitive to movements and vibrations are housed in these buildings, and the museum had to remain open throughout the works.
The structure that supports the courtyard is the roof of the basement; this is a ‘folded plate’ steel structure spanning 36m across the site to create a 1100m2 column-free gallery below ground. Expressed steel transfer beams and columns support an existing museum building as the main entrance staircase passes underneath. Access to the gallery is via the porcelain tiled entrance courtyard, known as the Sackler Courtyard, the world’s first public space to be paved in this way.
Sophisticated three-dimensional (3D) analysis, digital design and optimisation methods, together with early considerations of buildability and construction sequence, were important to understand the structural actions, and reduce the risks during construction, of this ambitious project. These techniques allowed the structural design to be visualised, understood and communicated in a way that enabled architects, engineers, the client and contractors to participate in its development.
Working with Amanda Levete's architectural practice AL_A, Arup provided multidisciplinary design services from competition stage through to completion of construction. This article discusses the key structural engineering challenges of the project.