Robotic construction of a self-balancing glass masonry vault: DEM study of stability during the construction stages

Self-balancing construction technologies were used for centuries in the building of masonry domes and vaults. Such construction techniques were made possible through the careful design of the block tessellation and the structural form, which enabled construction of complex geometries that remain stable without falsework. These historical masonry technologies have a disruptive potential for today's construction industry when coupled with emerging innovations such as novel computational form-finding approaches and robotic fabrication. This paper presents a structural analysis of the construction stages for a doubly curved, compression-only, 2-metre-tall masonry vault inspired by traditional construction technologies and built with a cooperative human-robot fabrication process. Two ABB-IRB 6400 industrial robotic arms were precisely sequenced to alternate placing a masonry block and providing temporary support to the unfinished structure. As a result, no form- or falsework was needed during any construction stage. The paper reports an iterative procedure based on the Limit State Analysis (LSA) and Discrete Element Method (DEM) to numerically study the equilibrium of the masonry vault during all construction stages.