The “Beyond Bending” exhibition at the 2016 Architecture Biennale in Venice advocates the logic of compression-only structural forms, not only because of their uniquely expressive aesthetics, but also in view of their potential for efficiency and the stability resulting from their geometry. The centrepiece of the exhibition in the Corderie dell’Arsenale, the Armadillo Vault, is an unreinforced, stone structure comprising 399 cut limestone blocks assembled without structural connections or mortar.

The vault, covering an area of 75 m² and spanning more than 15 m in various directions, has a minimum thickness of only 5 cm. Its shape is roughly triangular on plan, with four linear supports – three along the edges and one internally. Two large openings allowed the structure to be drawn round existing columns in the heritage listed exhibition space. One of the openings extends further down to afford a more interesting visual perspective and to create greater curvature.

The footings for the structure consist of 20 mm steel plates, which were designed to distribute the weight of the vault evenly over a large enough area to reduce the load on the floor of the protected building to the prescribed limit of 600 kg/m². A system of steel ties connects the supports and resists horizontal loads at the bearing points. The ties, which were necessary because physical connections to the floor were not permitted, were left exposed as a visual expression of the load-bearing system.?