Digital Stereotomy: Voussoir geometry for freeform masonry-like vaults informed by structural and fabrication constraints

This paper discusses new ways of digitally generating voussoir geometry for freeform masonry-like vaults. Through the combination of the recently developed form finding methods like Thrust Network Analysis (TNA), which facilitates the design of freeform compression-only surfaces and fast and flexible CNC-machining, structural efficient and expressive stone structures could be build which embrace today’s technological, economical, and ecological demands. This can only happen when all constraints in the process of design and materialization are fully understood and integrated in a smooth digital stream from form finding to fabrication. This paper focuses on the geometrical interdependencies between the generation of the voussoirs and the physical limitations of the fabrication on the basis of structural information. The principle is tested physically by cutting individual foam blocks, simulating the rapid and efficient cutting of natural stone with a diamond- wire saw. This is done on an experimental fabrication setup, especially designed for this research and based on four-axes CNC hot-wire cutting technology.