The Structural Design of Maillart's Chiasso Shed (1924): A Graphic Procedure

This paper shows how the geometry of one of Robert Maillart's most intriguing projects, the Chiasso Shed, was created using graphics. Originating in the sixteenth century, graphic vectorial equilibrium has been used for studying a wide variety of structural problems. Among other things, it allows a form to be adjusted so that it only encounters axial loads while guaranteeing equilibrium. Here, we see that the general appearance of the structure was determined with reference to a uniformly distributed load, and then concrete was placed along force trajectories. Maillart allowed for some geometric inaccuracies remaining with regard to the way he designed asymmetric loadings to be supported by stiffening members. In so doing, emphasis is placed on efficient axial forces, similar to our modern strut-and-tie approach, in the design of concrete structures.