The structure of the Grand Theatre de Rabat, Morocco: from digital design to local construction

This paper describes the structural design, from concept to delivery, of the Grand Theatre de Rabat in Morocco. The project includes an 1800-seat theatre, a large open-air amphitheatre, secondary experimental performance and rehearsal spaces, and a panoramic restaurant. It forms part of a national programme of cultural development located on the Bouregreg River between the ancient twin cities of Rabat and Salé. The complex nature of the programme and the form demanded an advanced digital process for the structural design. The most prominent example of the 3D process is the structural envelope wrapping around the entire building. Its concrete skin is stiffened by a regular grid of ribs, rationalised, but following the complexity of the shape and spanning in an efficient way that provides a continuous system, together with the concrete roof deck, to support the facade cladding. A highly automated parametric workflow was set up to create the geometry of the concrete ribs and shell, closely derived from the architectural design. The concrete ribbed shell and roof envelope went through an iterative process of rationalisation, informed by constructability constraints. The fabrication and delivery of the Grand Theatre de Rabat has been both a technical and a cultural challenge, with a London-led, digitally driven design process bridging to a local, traditional, analogue construction process.